squarewave,
This sounds like a very unique problem. When asking the others here, no one can recall a situation quite like you described. We also haven't heard of "bus mastering" before. So far we haven't run across an effect like this to look back upon for previous advice. We have noted similar effects that are related to screen refresh rates in Windows NT,2000 and XP that simply don't light up the bulbs on the diagnostic screen cause they change state too fast, but the history is always written as the printing of I/O # numbers catches up on the screen.
It might be best to call here so we can interactively ask you to perform some test. Also a LOGFILE.FIL file would be nice to have to review the history of events. We need to know what version you are running and whom you originally purchased from to get them involved.
Tech Support
CamSoft Corp.
(951) 674-8100
support@camsoftcorp.com www.cnccontrols.com