My relatively new (4 month old) Powerbook G4 is exhibiting a bit of a wobble when put down on a level table. That is, pressing on the lower right hand corner of the Powerbook, when it is open, will slightly raise the upper left hand corner of the Powerbook. Does anyone else have this problem? Is there a quick fix or should this be expected? It isn't too big of an inconvenience, although it can be a bit annoying. Thank you all in advance!