I have an iMac and a 24 inch Wacom Cintiq. When I put the iMac to sleep, it freezes and I have to restart both the iMac and the Wacom Cintiq.
How can I get around this?
I've had the same issue with my MacBook Pro (Early 2009).
Only occurred when waking up from sleep initiated by lid close.
Workaround I used was to switch off Automatically adjust brightness (Systems Preferences -> Displays). Hasn't re-occurred since – try that and see how you go.