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

Hummm.

Can you please do the following commands in terminal when you have a connection to your wireless router?

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport -s

and

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport -I

**Note that is a capital i not an lower case L

Then post the output here.

I have the same problem on my late 2011 iMac.

I had no issues before the update.  After installing 10.7.3, whenever the iMac wakes from sleep it does not connect to my wireless router.  Sometimes it asks me if I want to connect to a network, other times it doesn't even do that.

I am able to select my router manually and from then on it is fine, but the problem recurs the next time the iMac wakes from sleep.  When I select my router manually it does not ask me for a password, so it is definitely a "known" network - but it just refuses to connect to it automatically upon waking!

My wireless router is my only "preferred network".  I have tried deleting this and adding it again but get the same problem.  I have also tried manually installing the "combo" update of 10.7.3 (which seems to have sorted out some problems for other people) but this did not work either.

Interestingly, if I wake the iMac having previously logged out before putting it to sleep, but then wait a while before logging in, it does connect to my router!  I do have to wait a while, though - logging in straight away does not work.

Same problem here, never had an issue before but now coming out of sleep it goes through the motion of connecting but does not. I have to manually connect. I'm using WPA2 full 256bit encryption on the 5Ghz band. Same as the other poster, its my only wifi network in the list, and its set to not join any others. So far 10.7.3 seems to be a little buggy, I feel that the qualty of Apple software is going down hill. Aparct from Firefox I have no third party apps.

I'm also having the same issues. I had no problems before update, and now, every single time that it wakes from sleep, I have to manually select my Wi-Fi network... This isn't exactly a "fix", as Apple calls it.

Same here - No problems until applying 10.7.3...

I just fixed my issue, I downloaded the the combo update, turned off my wifi ran the installer, then confirmed drive and permissions, then turned wifi back on, now wifi works when coing out of sleep. I'll keep you posted if this changes but so far if I put the imac to sleep that would be it, but now it connects every time. Fingers crossed.

For those of us who are still experiencing this problem, can you please explain what steps you took to accomplish this?

Specifically, I'm not sure what you mean when you say that you downloaded the "combo update". I had my computer go to "Software Update", and I ran "Software Update". Did you do something beyond this? If so, what?

Once you turned off your WiFi, what installer did you run and where did you get it? How do you confirm drive and permissions?

Sorry, but I'm sort of a rookie and I have no idea what you're talking about. Thanks for any assistance.

Go to the apple downloads page and grab the Lion 10.7.3 combo update. Then open up Disc Utility and run verify drive (do that by highlighting the partion in the left hand side labled 'Machindosh HD' then click verify) After that completes run 'repair permissions' on the same partition, you dont have to verify beforehand.

Now reboot, turn off the wifi (just rick click the wifi icon and select turn off wifi) Now double click and run the combo update. After that has installed it will ask you to reboot, after signing back in verify the drive and fix permissions as before, reboot again and then turn on your wifi, hopefully this will solve your issue.

Forget that it just did it again  Apple really dropped the bomb on this update.

Okay. Just as an FYI, my iMac has been doing this ever since I left Snow Leopard and "upgraded" to Lion. I've never been able to have it reconnect with my WiFi network after sleep.

Mines working fine again today and mine has always connected, but my iMac came with lion built in. They changed the number of antenna in the later iMacs to three to support 450Mbps fata transfer rates over wifi.

I still have the problem today

My iMac came with Lion already installed as well.  I had no problems until updating to 10.7.3.

Same problem returning from sleep, but also the volume won't work as well. I try to restart or shut down and it just hangs (grey screen & spinning timer). Have to hold the power button down to shut down.