Scan disk for Sony DSC-T7 won't read in my card reader

I have this strange situation. The memory disk that came
with a Sony DSC-T7 has a small adapter to convert it to
the standard size Sony Memory stick. The disk that came
with the camera (32Megs) along with the adapter works
fine in my stand alone USB card reader. I have a 512Meg
Scandisk that works fine in the camera, I can download
pictures from the camera but the disk will not work
in my USB card reader?

Any ideas why?

Ken

Solved the problem. The stock Sony is a DUO
the Scandisk is a DUO PRO. My Dazzle 6 in 1 can't read
PRO. I found a firmware update for the reader which solved
the problem.

Ken