iMac "flashing" on Facebook

I am having the same problem. I just got my imac 2 days ago and everytime I open an image on face book and move my mouse/trackpad over it, it flashes. Anyone had any help with this yet?

Hallelujah! Somebody else is experiencing this! I have a 4-3 month old i7. I am a member of an on-line photography group on Facebook. When I am working on uploading my photographs, my display will flash in my face randomly. The flash is intense like a strobe and invariably happens when I am trying to peer intently at a photograph. I set up an appt. for a phone call with an Apple respresentative and he basically couldn't help. So I want to know about this, too!

This was driving me crazy! Even had a scheduled phone call with Apple Tech Support! They were no help at all!

This seems to be linked to Safari. When I switched to using Firefox as my browser, the problem entirely went away! So I am on Firefox for the duration!

Yep same thing here. I have spent about 2.5 hrs on the phone to apple support this afternoon and all we have come up with is that it is only in safari and only seems to happen when I make the window bigger. Once it hits a certain size thats when it starts. oh and it seems to be confined to just one page on facebook. I'm told they are working on it and will contact me on Monday (hopefully with a solution). Will keep you posted if I get anywhere 🙂

Let us know if you come up with another solution!

What we did was as follows: In Safari, click File>export bookmarks, export them to Desktop. Open finder, click on "Go" in the menu bar and hold down Option on the keyboard so that "library" appears. Click on Library, open Preferences and pull all com.apple.safari plists to the desktop. Go back to Library and pull Safari folder to desktop. restart mac. In Safari, click on File>import bookmarks and locate your bookmarks file.

Just picked up a new iMac and I am having the same issue. Got the computer yesterday and I am dissapointed that this is going on. Just as the previous posts ahve mentioned, if you click to enlarge a photo on Facebook and then see the screen where the photo is surrounded by black area you will see a crazy flashing screen pattern all around the photo as you move your mouse around. I pray this is not a hardware issue. Does anyone think this is Hardware or do you think its Software?

This is clearly a software issue. When I use Firefox (which I do now), it doesn't happen. I can't believe that Apple hasn't addressed this issue. Of course, they probably say that it is purely a Facebook issue - but I don't hear complaints cominig from PC users. Fortunately a friend of mine also has the i7 and is having the same issue. I tried all of the things that BM7 talked about, too. Didn't help. Here is what we think we have figured out. We think that it has something to do with having both the trackpad and mouse attached at the same time. So if you have both, try disconnecting one or the other and see if it goes away. By the time my friend suggested that, I had already migrated to Firefox. So if it quits working, I will try Safari again, etc.

The only other difficulty that he had with his i7 was a cooling issue. It tends to run hot. We both process photos for hours on end and while it is in that mode, it gets very hot. He has already had his replaced once by Apple. He keeps a little fan at the back of the iMac which just keeps air blowing over it to help with the cooling.

Good luck! Other than that, I love my new. Mac.

Mine was fine until I upgraded to Mountain Lion, ever since then I have experienced the same problem. I have to use firefox to avoid the problem.

For anyone one who's health suffers from bright flashing lights they really need to avoid new Safari until apple fix this...

Since coming over from Windows I have not been very impressed with Apple products... not sure what all the hype and fuss about apple is all about!!

kaz28 You just solved this problem for me!!

I have a 27" iMac and usually have Safari window stretched for about 80% of the screen width. Facebook photo viewer was blinking as crazy. After reading your post I resized the Safari window width to a smaller size and blinking gone! For me it works fine if the window is less then 75% of the screen width. If wider or in the full screen - page blinks when the cursor crosses a border of a photo.

I was having the same issue in Safari only but not Chrome which also uses Webkit. And like kaz28 suggested, once I shrunk the window to 75% or less, it stopped flashing in Facebook.

Same problem here. 27" iMac just upgraded to Mountain Lion and now really annoying flashing squares at each corner. Kaz28 thanks for suggestion on window reduction...has saved my eyesight. I'm keen to hear what apple support say about the problem.

BM7 - Thanks for your post. This resolved the issue on my iMac.

BM7 wrote:

What we did was as follows: In Safari, click File>export bookmarks, export them to Desktop. Open finder, click on "Go" in the menu bar and hold down Option on the keyboard so that "library" appears. Click on Library, open Preferences and pull all com.apple.safari plists to the desktop. Go back to Library and pull Safari folder to desktop. restart mac. In Safari, click on File>import bookmarks and locate your bookmarks file.

Same here - but shrinking the window is no option since I use Safari in full screen mode. I hoped it would be gone in 10.8.1, but it still the same. Apple, please FIX IT!