I had strange connectivity issues with my 920 for a little while, it wouldn't detect as a drive. I disconnected my old iPhone (I was taking stuff off of it and it was still connected) and boom... 920 detected as a drive. Not sure why that would even matter but it did...
thanks for the help "inteller" what if the original poster can't just switch OS, if you can't help them then why bother saying anything. I myself am in the same situation and was looking for help, not sarky comments.