ram 3 gb
Intel® Core™2 Duo CPU E4600 @ 2.40GHz × 2
graphics Intel® G33
64 bit ubuntu "quantal" (pae kernel") x-86
That is a really old graphics chip.. And intel chips have never really worked well to begin with. I would suggest lowering your shader quality in the options and seeing if that makes it playable.
well it used to work on this very computer then it didnt...something must have changed