Hey Ian,
I am having all kinds of trouble with accessing my PDW-U1 since upgrading my OS to Win7/64.
Without the Sony software my computer sees the disc, but not in the typical XDCAM structure.
I updated the firmware to 2.54.
When the unit is connected to the PC and I insert a disc, the red error light starts blinking. When the unit is not connected, the error light is not there.
I have tried 3 of the most recent driver files from the sony
XDCAM site but none of them seem to work.
Any suggestions?