Can't put iMac to manually to sleep since Mavericks

[seniorchang]

Since the upgrade to Mavericks on my late 2007 iMac I can't put it to sleep manually by cmd-alt-eject or through finder and not even by the sleep button on the back. The display just goes black but cpu/hd keeps working.

The automatic sleep function after a certain time is working correctly though.

Any ideas?

 

[Freyqq]

Since the upgrade to Mavericks on my late 2007 iMac I can't put it to sleep manually by cmd-alt-eject or through finder and not even by the sleep button on the back. The display just goes black but cpu/hd keeps working.

The automatic sleep function after a certain time is working correctly though.

Any ideas?

Same exact issue, but with a new 2013 rmbp 15" with 750M. My current theory is it is a graphics card driver issue, as it only seems to occur when the 750M is active.