fm on mac/steam crashing

i bought fm 11 on steam (my first purchase on it) when it came out. i've not had any problems until now.

the other day i (stupidly) ran out of hard drive space while playing fm11. i deleted a load of old guff to make space on the drive but when i try and play the game, it gets to one point (right before i play a match) and it crashes. i've tried uninstalling and reinstalling both steam and fm but that hasn't helped. i've also validated the files. steam say that this isn't their problem. anyone got any ideas? i'm desperate!!!