Javascript bugs in Safari 6 on Mountain Lion

I've had two of these 15" Retinas with the same exact problems (and believe me, they go deeper than Safari; see UI desktop switching lag, long wakeup times, random logouts, etc.). Everything is enabled in Safari, I've called Apple support (who referred me to the Apple Store to no avail), I've reset PRAM, and I've clean installed OSX (without the migration assistant). Every major retina-specific update fixes the problems computer-wide for about 1 day, and then everything comes back and gets worse and worse. Again, this has occurred on both of the rMBPs I've had. I've also tried the webkit version of Safari, but unfortunately that crashes on casual browsing.

This is pretty ridiculous. I'm awaiting the arrival of a 3rd rMBP replacement since this one's hinge is already coming loose and the genius who looked at it at the Apple Store had a screwdriver slip that resulted in a 3-4 inch long scratch in the aluminum.

(PS - thanks for the suggestions, btw. Not trying to be cantankerous here... this was just the biggest present I've ever given myself for acceptance into graduate school. Instead of treating myself to the ultimate computing experience, I have this embarrassing machine that goes ape when I try to surf the net while my classmates do so with ease on their $300 budget laptops.)

My sympathies. I can imagine how frustrating that is. In the final analysis, it seems too coincindental that two MBP Retinas would have the same hardware problem. In more than two hundred Macs purchased over the years, I've only seen it twice. It's even more rare for the same person to have the same hardware problem. It also seems odd that you'd have the same two corrupt user files, unless caused by a third party app. Seems like the most probably culprit is a conflicting app or system file. Mountain Lion is very new; and conflicts appear often.

In the last three months, I've purchased five different macs for staff and family, plus upgraded a couple to mountain lion. I had the dissappearing cursor mouse problem talked about in another discussion group, but it was solved with a clean install, avoiding older apps (no migration) and only installing what I truly needed. I also had some various weird occurences resulting from the latest version of Transmit — a great app, but whose menu bar feature caused some spontaneous sleep issues etc. I simply had to turn off that feature. And another weird problem happened with Account Edge. Finally, I too had a hardware issue (hard drive failure) that corrupted my files. It's rare, but it happens on all machines. Still, very unlikely for you to have the same hardware issue twice.

Have you tried booting in safe mode (Hold the shift key when booting) to turn off third party apps and operate with minimum extensions? See if you can then replicate the problem. If not, it would appear to be a third party app startup conflict. If you still have problems, try creating a new user account to see if the problem occurs from the new user (this checks to see if you have a corrupt user file). If you still have the problem, try booting from a start-up drive. Finally, if you still have problems, then do the hardware test. (Press D during startup.) After all these tests, call Apple Support and INSIST on having the matter escalated to level two support.

One more thing you can do is google: "Mountain Lion problem" plus the name of each app in your system to see if others are experiencing similar issues.

My apologies if you've already done all of the above.

Ok i have to apologize here as i i've been too busy to give people the solution for MY problem:

Safari doesn't like a div video container background or/and the video tag background itself to be stylized via css. At first it seems to work properly but each mouseover slows down the whole page in that case, and of course it gets even badly worse when you create a javascrpit plug-in above the video tag.

I juste removed the CSS rules and evry thing works fine.

The demo here: http://www.digitalvideo.fr/test3 (see contact form).

Take it easy

Just wanted to say, received my third MBPr and I'm having all of the same Safari problems. On day one, Safari behaved perfectly. By day two, I'm once again having gifs that stutter, missing blocks of data, blank white pages when I try to go back a page, etc. I'm not sure if this is a Javascript issue I'm having, as single gif images don't load correctly on a blank page. All I have loaded on here is Office 2011 and Photoshop. At this point, after three MBPrs, I think it's pretty safe to say that Safari bugs aren't just a coincidental occurance for my laptop only.

You maybe replacing the wrong hardware. It could be a modem, router or cable issue. Try replacing your cable modem and/or router. Then consider the coaxal and ethernet cables.

Last month I had email problems — some mail not getting through. At first I thought it was Mail. Then I suspected my host/server, but no one else on the server had the same problem. Someone suggested it was my modem, and sure enough the problem was instantly solved when I replaced it with a newer model. I never would have guessed. I can't explain why, but it clearly worked.

And now that I think of it — that's when my Safari problems dissappeared too. I thought my Safari issue was resolved by me fiddling with settings and a corrupt file, but maybe it was the modem all along.

This is definitely not a connection issue. I'll humor that idea for a moment and say that this happens at school, home, coffee shops and friend's houses. I'll also say that these issues do not occur on my wife's 2009 MBP with Mountain Lion and Safari. A fantastic decription of the rendering issues can be seen here: http://installingcats.com/2012/08/02/safari-6-macbook-pro-retina-mountain-lion-p roblems/

As I said, I have the same machine — 15" Macbook Pro Retina, Mid 2012 — no issue.

And I too primarily use Photoshop. However, I do not have Office 2011.

When you did the clean install, did the problem occur before you installed Office?

Clearly it's not a universal issue for all machines, but it's possible that it's a hardware issue — like a graphics card.

I use my Macbook with a desktop monitor; only use the Retina when I'm mobile. Have you tried using a monitor?

Just upgraded to a 15" Retina MBP. Having these same issues: white blocks covering web sites (particularly troublesome in GMail) and disappearing text whenever I type in a web window.

Saddened to see this is an unresolved problem, but curious that the few reports I've seen on the web all seem to involved 15" retina Macbooks.

I upgraded from an early 2008 MBP, which suffered from none of these problems.

Edited to add: This all occurred without extensions, then with extensions, then with those extensions removed.

Do any of you happen to have Spotify installed? Just curious don't flame me just yet!

I had this problem on my MBP with Lion and Safari 6, now also experience the problem on my new MBP with ML and Safari 6. So it's not just retina MB's. It's just super annoying and was actually hoping the latest Safari update would have fixed this, but nothing still. I have never had to close and restart a browser as much as I have to these days in order to have it function.

Huh. What a weird and frustrating bug. Amazing that it could totally screw up the browsing on a high-end, new laptop, but have no effect whatsoever on my 2008 MBP.

Per the question earlier, no Spotify on this end. Here's a couple photos of Safari derping out:

I find the first one really funny because it's the glitch occuring on the email for this very topic. But as you guys can see, it doesn't just happen on Gmail. Pretty much any site I've visited is capable of glitching out in one way or another. The errors above are with a fresh install of OSX ML 10.8.2 with no added programs. Apple, get it together. Quit suing people and focus on the fundamentals: a hassle free web browsing experience. It's almost 2013 and yet Safari is in the dark ages.

Speaking to an Apple representative now. A Safari reset seems to have helped, but I worry about the problem reappearing once we're off the line. Not even having trouble typing right now.

I have noticed that of the three rMBP with this exact problem, a Safari reset does help a little bit... for about 30 minutes, lol. Funny how they suggest a Safari reset when an entire OSX reload doesn't help.

Yes, I expressed this exact concern and he then told me it's a known issue that's being investigated. I think someone else reported this earlier in the thread. His advice was simply to keep resetting Safari when the problem arises, and also to see if the "Open New Window / All Windows from Last Session" option had any effects. Not sure how that relates, but I'll play around with it, I suppose.

What's sad is I'll probably be migrated over to Chrome and completely comfortable with it by the time this is fixed.