Freeze after Sleep

After waking up my Mac Pro from Sleep Mode he starts but within an minute he freezes. I can still move my mouse pointer but that's it.

I neither can click anything nor can use keyboard shortcuts. So I have to shut him down by holding the power button and reboot him.

Does anyone have the same problems? Or at least a solution?

Are you leaving any applications open when you put it to sleep? I wonder if one of these is getting upset after waking up? I have a tendency to close down all apps before I put my Mac to sleep. Perhaps as a debugging step you could try that? Close all your apps before putting your Mac to sleep and see if it now recovers correctly. Please report back to us!

Before I left some Apps open (like Browser or IM). But even with all Apps closed he still freezes.

I would say install your os again this was an issue with my MacPro ... Not a big deal but a small pain in the rear.
Good luck.
Fijiji

Also try resetting the SMU.