iMac not waking up from sleep mode (10.5.6?)

I think yes. On 10.5.5 my imac has no problems with the sleepmode. Since the update on 10.5.6 the imac won't wake up form sleepmode 1 of 10 times. In my system.log, there is an error, who is displayed 1000times or so called "kernel AppleFWOHCI_AsyncReceive::waitForDMA - context not going inactive." maybe this is the casue of this sleepproblem???

Yes, I saw this message also and even started topic on this here in another thread.
Since resetting SMC, I don't see this message and computer sleeps/wakes up properly both automatically and manually.
So try that.
So, may be that message indicated something that was the reason for the problem.
Thanks

Do you use a non apple wireless mouse?

logitech mice will cause problems like you've described, if its left on when computer is in sleep mode.

If this question directed to me, then the answer is NO,
I use Apple wired mouse connected via keyboard.

Thanks

After a week or so, the problem came back.
Now I'm completely puzzled what triggered it:
No new software have been installed, no changes in configuration have been done.
It seems like something goes wrong in this area over time.
I guess, I need to try to reset SMC again, but doing this every week is a crap, really.

Thanks

I'm also still suffering from this issue despite trying the fix earlier in the thread.

----I'm also still suffering from this issue despite trying the fix earlier in the thread. ---

no, it doesn't seem like the SMU is the solution, how many are still having sleep problems after 10.5.6? on 24" Imacs?

I was having the same problem...Aluminum Intel iMac (debut model) with all the latest updates.

I repaired permissions and guess what, it worked! I was very skeptical!

Dave

I've got two iMacs (one intel aluminum, one G5) both are having the seep issue. I can't trust either machine to wake up now (+80% they don't wake up). Basically every time I put them to sleep now I have to save all my work. Of course Applecare has expired on one machine and I never purchased it on the other so when Apple's updates break them I'm the one getting screwed over.

This started as a mild inconvenience of unplugging the machines once and awhile to get them running to me questioning why I've spent so much money on this company over the years.

Very very disappointed in what's going on here.

I repaired permissions and guess what, it worked! I was very skeptical!

unfortunately, reseting the SMC, or the pram, or the permissions do not work in specific cases, I know for sure that the 10.5.6 update fixed 1000's of people's sleep issues with 20" imacs, but has now caused an issue with 24" imacs....

so i imagine we'll have to wait until 10.5.7... it is strange that I can remember for i think going on 15 to 20 years, apple constantly has problems fixing sleep issues... it really is amazing that they don't check this first???? with ALL models back atleast 3 years...

and you have to let it sleep for 6 hours or so, before the problem occurs....

Jon.

You can add me to the list of iMac users that are having this same problem.

UPDATE

Above I said that my not-waking-from-sleep problem was solved by running Repair Permissions--turns out the problem is not fixed!

I put my computer to sleep last night and it wouldn't wake up this AM (after at least 7 hours or so).

Arg.

Join the crowd....

I'm also having problems with my 20" iMac waking from sleep. About the same time that started, I experienced a problem where none of my Firewire drives would not show up when connected. For me these problems seemed to start when I installed new software for my scanner (NeatWorks for Mac), but that may have been a coincidence. After uninstalling NeatWorks, I still have trouble waking from sleep about 25% of the time.

Repair permissions reports the following warnings, that I find a little disconcerting:

+Warning: SUID file "System/Library/Filesystems/AppleShare/afpLoad" has been modified and will not be repaired.+
+Warning: SUID file "usr/bin/setregion" has been modified and will not be repaired.+
+Warning: SUID file "System/Library/PrivateFrameworks/Install.framework/Versions/A/Resources/runner " has been modified and will not be repaired.+
+Warning: SUID file "System/Library/Printers/IOMs/LPRIOM.plugin/Contents/MacOS/LPRIOMHelper" has been modified and will not be repaired.+

I'd love to hear from anyone who might be seeing any commonality here. I'm accustomed to leaving my apps open at night and putting my computer to sleep, but now I close everything out to avoid possible problems from having to reboot when the machine won't wake up.

I'm suffering from the same problem.

24" iMac that didn't have a sleep issue problem until 10.5.6. Now most of the time it will not wake from sleep. Have not tested the 6hr limit yet, though it usually wakes from sleep if I do so after only an hour or two.

I have a logitech wireless keyboard and mouse, but had them since before the 10.5.6 update and they didn't cause any problems then.

I usually solve the problem by holding down the power key until I hear the hd (or a fan) spin down. Wait 10 seconds, then startup as normal. Sometimes the mouse and keyboard won't work, but I gather that is a different issue.