Ok, I don't know if you solved that problem yet or not, but since nobody else posted I'll try and answer!
The Bluescreen CAN'T be related to the flash drive, since you only saved programs there that are irrelevant to windows itself, or your hardware... (like drivers and stuff)
If you get a bluescreen again, try to read EXACTLY why it was caused...
I get bluescreens from time to time too.
Mostly you only need to update for example your graphics driver...
(I have that problem because of the hybrid graphics but that's another story...
I think your notebook doesn't have hybrid graphics.)
Possible causes for the Flash drive problem:
Usb port damaged,
Flash drive damaged.
I can't think of more...
Solutions:
Try to use your drive on other computers to make sure it still works properly...
Try to use something else on that USB port...
(No matter what)
I personally think the problem lies within the flash drive...
So... check it out and pm me about the answer, maybe it's a whole different problem.
PS: what service pack do you have installed?