Q: 10.7.3 - late 2011 iMac - update broke returning from sleep and connecting to wi-fi...

When you do a clean install you have nothing connected, and yes always repair permissions before and after , many people are still having this issue even after this new update though. Are you using a wired keyboard? I am using the standard wireless one that came with the iMac.

Yes i'm using my wired keyboard, i gave up on the wirless keyboard that came with my mac as it ate batteries up so quick, i gave it away and saved myself the batery head acke

I'm sorry you and some other's are still have problems, appe rolled out the 11D50b quick so your fix shouldnt be far away 

Cool i hope its fixed your Wifi

Thats odd, maybe its something to do with the keyboard, odd your keyboard went though batteries, mine last about three months in my keyboard if not more and I am on it 6 hours a day probably. Anyway thanks for the extra information, I just rebooted my router so the iMac had to grab a new DHCP Lease and it connected via keyboard that time, very odd.

I spoke to soon my iMac just lot its Wifi Yet again and with what Apple rolled out after so many complaints and Its Still Not Fixed !!!!!

Your lucky with your wireless keyboard battries lasting so long, my magic mouse lasts ages a bit like you keyboard, and i prefer my wired keyboard with my number pad to the right

Welp, installing the combo update didn't really solve the problem.

So I did some digging around and realized the problem mostly has to do with waking up an iMac with either the Bluetooth mouse and keyboard, and pressing the power button to wake the iMac is a workaround. I went to the bluetooth prefs and unchecked then re-checked the "Allow Bluetooth devices to wake this computer" preference, and the problem seems to have gone away.

I started having problems after updating to 10.7.3 with my iMac not connecting to my WiFi when waking from sleep. Read thru this long thread and tried the easiest thing first -- repaired permissions. A day later every thing seems OK. So repairing disk permissions worked for me.

To all those having problems, I recommend repairing disk permissions first. It is easy and fast and may very well solve the problem.

Repairing permissions did it for me!! And it's a lot faster now establishing the connection than before

Thats really odd because the first thing I do is repair permissions both before and after, its odd how some things work for some and not for others.

Since this seems to work for some, and not for others, could you guys please mention what your machine is so that we can help narrow it down? If it works for, say, a 2011 iMac but not a 2010 iMac, that might be helpful. There have been many issues in the past that are machine-specific.

Tried repairing permissions but it didn't work for me. Ended up downloading 10.7.3 from the AppStore, using another machine, copying that onto the stricken machine and doing the painless reinstall OS X thing. That seems to have nailed it!

FYI, doing the standard update on my iMac gave my none of the problems I'd experienced with the laptop.

Just glad I had two computers, otherwise it may hve been dicey!

iMac midd 2011 21.5 i5 quad core,16GB ram. 10.7.3 Combined update.

Orange Livebox internet supply

I ran my disk permision repar before and after the 11D50b combined update instal.

This seemed to make my airport wifi behave,  but soon enough later that day and ever since when the mac goes to sleep 2mis or 2 hrs it looses it wifi and i have click turn of wifi and turn it back on to get the airport wifi to work properly again.

It seems strange that Repairing permissions have workes for some and not for others like myself...

EFI Firmware update just released to correct this issue:

http://www.macupdate.com/app/mac/31198/apple-imac-efi-firmware-update

so I'm NOT crazy!

tmazzulia, I thought you were on to something, because after I disabled "Allow Bluetooth devices to wake this computer", my iMac connected to my network after waking up using the keyboard.  The first time...but not again...

I have a late fall 2009 27" iMac...my network (and internet) is provided by an Airport Extreme N Base Station.  My iMac connected to that network automatically after waking from sleep (primarily by pressing my Magic Mouse) until I updated to 10.7.3.   Now it only connects automatically if I wake it up by pressing the power button...and via the keyboard/mouse after eight hours plus of sleep.  I have tried EVERYTHING recommended by multiple users in multiple threads on multiple Mac-related sites...and nothing has worked more than once.  Except using the power button.  I do not have any wifi drop problems...although I have experienced difficulty streaming audio via the optical port on the Apple TV2 since the last iTunes/ATV updates. 

I've submitted a couple bug reports to Apple...over and out until the next OS X update. 

welp, the EFI firmware update didn't fix it. Really frustrating.