When in pboy inventory selecting a stimpack or any other item but mostly stimpacks ,will cause game to stop working , happened many times , running fresh windows 7 ultimate x64 sp1, 1 gb video, 8 gb ram, 2 quad cpu q8200 @ 2.33 2.34GHz all else up to date, latest patches. please, anybody with any suggestions...
Thx

Go back to an old save, atleast an hour or more.
Your current file is most likely corrupt, there's basically nothing you can do.