Vista64 and Floppy Drive

For unknown reasons, Windows Vista64 sees the floppy drive, but cannot read, write or format any floppy media.  This is the error code that I get:  "A:\is not accessible The request could not be performed because of an I/O device error. Or  Windows was unable to complete the format".

I've tried swapping a brand new floppy drive, no go.

I've tried swapping the floppy cable, no go.

But it works under "Safe Mode".  I can read, write, format to the floppy drive at will.  am I missing something in the 64bit world?