The 950 I had was never recognized by my Win 7 64bit PC, yet the 350 was recognized. Sony cs was worthless. I then tried the 950 with my Win XP netbook and it was recognized. Sony cs said the driver was the same for the 350 & 950, but I question that. Anyway, try the 950 with another computer and see if it gets recognized. If so, nothing is wrong with the 950. I suspect a flaky 950 driver is to blame. The 950s seem to work with some Win 7 PCs, but not all.

EDIT: I no longer have my 950 and my 350 is for sale. So I'm not concerned about fixing the driver issue. However, I wanted to post my experiences so the OP can see that regardless of how many people post "it works fine with my setup" there can still be issues. BTW, I've never really understood the mentality behind "it works fine with my setup" posts as they do nothing to help out anyone.