One of our list members (David Grissom) has been able to show that there was a problem created in the M100 file directory when switching in and out of CP/M. To do so took a fair amount of effort so thanks David.
With a good deal of effort, David, Philip and I dug in and found the problem. I've implemented a change that seems to address the problem. Doing some more testing, and I've handed it to Philip and David for their gruelling workout. When it looks good, I'll be posting an update to the REXCPM wiki for a the updated RXCMGR ROM, as well as the utilities (which have had minor changes only). Steve