well, its not like your useing an old machine. So the graphics card, even though its built into the mother board, by the sounds of your discription, should work ok for maya.
I mean if there are any issues with the card, usually you just get some funny graphics displayed in your perp view or something. So i have douts its not your card thats causing it to crash.
But thats just my thoughts i may be wrong.
Have you tried re-installing ? its the first thing i would be doing.
Fail that, i would even try getting your hands on another copy of maya PLE. You never know the version you have maybe corrupt for some reason.
Check these things out before you go spending heaps of money on a new card.
Also, i think on the alias website, it tell you the cards that they recommend you to use with maya, to avoid incompatiability issues.

Best of luck, :-) let us know what the problem was when you get it fixed.