career mode not playable-- CTD only

Hello to all
I hope someone can help me here.
I have spent the last two weeks trying to get this game to play correctly in career mode but have had only one mission that I have been able to play. Since then I get a CTD when I try to select any crew assignments when in port. My PC just locks up and the screen goes black and I have to reboot the PC. Sometimes the crashes are so bad that it stops other programs from working and I have to re-install the drivers for these.

I have read all the links here and have re-installed the game twice and patched to version 1.4b but still these CTDs occur.
I'm not having much fun with this!

My PC specs are AMD3400 cpu, 1gb ram, ATI 9600 Raedon 128mb VGA,WinXP sp2,--pc has been defraged- registry cleaned etc. It runs CFS3 and BoB WOV ok.

thanks
chuck