Waking from Sleep problem

Hello,

Love my new MBP, but have a problem when it wakes from sleep...

If I leave the Mac alone for a while it goes to sleep.

Sometimes it come back from sleep when I press a mouse button and asks me to logon.

Sometimes it sort-of comes back, only the screen remains blank and I can see the mouse pointer with no logon password box! Pressing keys does nothing except makes the 'beep' noise like a train.

Am I missing something?
How can I get it to wake from sleep okay?


THanks,
M

I have had similar problems, and i am not sure why...