Entering vehicle leads to CTD

[TOOMSKI2000 0]

Looking for help with this one !

system specs :

p4 3 ghz

2gb ddr400 ram

ati x1950 pro

ati drivers 6.14

sound blaster audigy 2

intillimouse optical

Just re-installed windows ( XP pro service pack 2 )

and only installed graphics drivers, mouse and sound card

and of course a fresh clean copy of arma that i updated to version 1.5 ( UK copy )

and when i play the game EVERYTHING works fine, sound, weapons, graphics etc but when i try to get into ANY vehicle whether online or in the editor the game crashes to desktop and shows up a smallish blue square that has no info, text etc in it and only says arma when you place the mouse cursor over it. i am at a loss to this as i have had no trouble with the same setup not even 24hrs before ( happily playing evolotion online for hours with no trouble ) and i would be graefull if someone could give me an idea for this as i have exhausted the different graphics options, hyperthreading on off option etc etc etc !