[dmcrooks]

I have not removed any item installed by the PT installation, including the Digidesign Eleven Rack preference pane (even though the message "device not connected" appears when I open it).

I don't have any Mbox control panels / preference panes...I use a FW 1814 which has its own app.

For the record, although it still happens to me from time to time, I've been able to minimize the occurrences of 6101 errors somewhat by unchecking the "ignore errors during playback..." setting in addition to continually throttling the H/W buffer size.