Since upgrading to 10.7.4 the screen savers on my iMac freeze

Actually it's not the screen saver I've just worked out. (All basic apple standard screens avers) but ithe problem seems to be trying to wake the screen up when the screen sleeps.

Right now I've set screen savers to 'never' and iTunes is happily playing but I can't wake the screen up. It's just glowing black. I can use the volume controls.

If I SSH into the mac from my other mac and run top there is not much happening. iTunes is using about 2% of my CPU and the backupd says it's 'stuck' all other threads are 'sleeping'.

Naturally I can't run the Console app without forcing a reboot of the mac to gain control of it again. I've looked in various log files in /var/log/ but nothing stands out as weird.

I've repaired permissions, verified the disks etc just to be thorough but that's not helped.

Curiously I just tried to remote-desktop (using ARD) into the iMac but it says 'connection failed'

I've fixed the ARD issues — it's unrelated to my problem.

The next thing I am trying is turning off the need for authentication to wake up from sleep or screensaver.

Looking in Console.app now I see nothing too odd.

I am seeing a lot of

'PM kernel: en1 duplicate IP address 192.168.1.153 sent from address c8:2a:14:23:75:e1' though but I can't

1) work out what device c8:2a:14:23:75:e1 refers to, or

2) see how that would be related to my issue.

Okay so without requiring authentication to wake up from sleep or screen saver all is fine. So my workaround is now to turn off the need for authentication when waking up from sleep. That's not really ideal but it will do until a proper fix is found, and now I can turn my screen saver back on for what it's worth.

Yep - done that and no, time machine is not the culprit. The culprit seems to be realted to the authentication / security system which borks when trying to wake from sleep or screen-saver.

update: now even without the need to authenticate to wake up from the screen saver I am getting the same result. and ARD won't connect to the iMac now. I can SSH into it and top shows nothing much happening at all.

This is really annoying me

ARD wont work because I have remote desktop running on my iMac. sigh.

No I don't have any sort of BluRay player.

I've come across this discussion which also relates.

https://discussions.apple.com/thread/3784621?answerId=18431484022#18431484022

No solution on offer yet though

d

Hi @FlyinPhil, I also suspected the security settings so, to experiment, have had my iMac running without the need to enter a password to wake it up from screensaver or sleep. The problem still persists however so that's clearly not the culprit.

I tried setting the screensaver to the simplest one possible - just shows the iMac's name - but this made no difference.

On a hunch I tried resetting the PMU of the iMac by shutting down, pulling out the power cord, leaving it for a while (overnight in my case), plugging the power back in, waiting a minute or so, then powering up. This seemed to fix the problem for a while but then last night it happened again.

Now I am trying the following. I've created a new test account on the iMac with the screensaver set to come on in 5 minutes, requiring a password to unlock, and energy saver set to sleep the screen in 15 minutes. I'll see if the issue recurrs. If so then it must be a system wide issue. If not then it must be something specific to my user account.

Note this issue does not occur on my 17" MacBook Pro, Mac Mini, or my wife's 13" MacBook. Only my 27" iMac.

If, after a day or so, the issue does not recurr on my test account then I'll try migrating all my apps and settings etc over to a fresh account on my mac and see how that goes.

I'll report back here with progress or things I discover.

Cheers

Dave