I have P2011 and works fine but sleep the pc has a bug. When the pc is booted the desktop appear and i can sleeped the pc by the K-menu, if i try many time to sleep the pc at some time it fails and the pc don't sleep.
When the sleep in the K-menu fails i can used the command #pm-suspend and it works.
I suppose there is a log file in /var/log where i can found info, can you help me?
Add: it is my /var/log/messages http://www.kensan.it/tmp/messages.txt
Add2: i have several problem with my desktop, maybe it is not only a sleep problem, also dolphin dont works well, paste clipboard into desktop dont works well. Can i resinstall KDE? or plasma?