This did fix the problem, BUT ... it is specific to the user. So, just logging as ourselves (administering) onto the Terminal Server wasn't enough. It also didn't work logging onto TS as ourselves and then logging into Sage 100 as the troubled user.
The user had to login to HER machine, then onto the TS session as herself, and then onto Sage 100 as herself. Then Reset the Panel, and all is good.