Hi Mike,

It is basically any, and all MIDIs.

On another group that I belong to the author of vArranger software which is specifically designed for the SD2/SD4 confirms that the issue does indeed exist with the SD4 and Win7, especially if you are doing a non-trivial MIDI sequence.

He says that there is a new version of Ketron firmware that is shipping with new models that does work well with Win7 as far as USB. This is version 1.31 but it is also reported that with V1.31 the MIDI interfaces on the SD4 don't work well. It is hoped that there may be a beta V1.32 of the firmware that addresses both the USB issue as well as the MIDI interface issues.

Also, he reports that using external USB to MIDI adapters appears to work well with Win7 and the SD4 with the older firmware so that will be my first round of testing.

This is part of the information that he provided:

"On windows 7, some messages are not well interpreted and this cause detunes and mutes..... (Burt - This is exactly what I am experiencing!)

When I asked to ketron about this problem, they told me that the SD4 is working well with Windows 7. The fact is if you stress it a litle bit, that is false.

The SD4 is still working with Win 7 if you use an external MIDI USB cable, like Roland UM-ONE."

I will probably need to upgrade the Ketron to V1.30 which is the last official firmware version from the Ketron site. Once I have tested the external interface, and heard back from Ketron regarding firmware update availability I'll update this thread.

Thanks again,
Burt