Readyboost made my card reader quit working

I have a Gateway with a built in mulit card / SD card reader. I have used
this many times to add and delete music, movies, pictures etc from my Sony
Memory Stick Pro Duo, worked GREAT. Then i decided to get a Sandisk Ultra II
SD card to use as Readyboost. I inserted the card and it worked fine for
Readyboost. Later i ejected the card fine and went to use the Pro Duo in it
and when i inserted it, the computer recognized it and showed it as a
reomvable drive but when i clicked on it to open it, all i keep getting is
"insert disk into Removable Disk" message. Since the computer had another
issue and had to go in for warranty work i thought it was that. Before i sent
it in they had me restore it to the original configuration like new, so i
did. When i got it back i again popped my Memory Stick Pro Duo in and it
worked great. A couple minutes after i was done i decided to pop the Sandisk
back in and again it worked great for Readyboost. Then later, i ejected the
Sandisk which removed ok and all was fine. Then i installed the ProDuo back
into it and got the same message. It actually sees the card and it shows up
as removable but wont let me access is and gives me that same "insert disk
into Removable Disk" message. I have so far uninstalled the built in card
reader and all its software, re-installed it. Went to Gateway and got the
Vista memory card reader drivers. Checked Microsoft for driver updates and
updates in general etc etc etc... What next? Any suggestions?