Chris,

In order to compare XP to Win 7 / 64, I downloaded and installed to appropriate driver for the Roland SC-8820. In the MIDI / Audio driver set up window, under MIDI output driver the following alternatives showed up:

1: Roland SC-8820 Part A
1: Roland SC-8820 Part B
1: Roland SC-8820 MIDI OUT

This is similar to what I saw earlier under WIN 98 SE.
The Piano Test in the MIDI Output Driver Wizard gave results for Part A and B (of course nothing for MIDI OUT).

With your driver Win 7 / 64 only Roland SC-8820 showed up. Can this be an indication that there is a minor flaw in the driver you developed?

Tonnie