FoxPro applications have some oddities on a terminal server that I'm not personally familiar with since I've managed to avoid FoxPro. The links here and here may offer some useful tips for running FoxPro applications on a terminal server.
However, on the off chance that it's not a FoxPro problem, it sounds like you installed the application while the terminal server was in execute mode. If you run an installation program called SETUP.EXE or INSTALL.EXE, TS is smart enough to prompt you to start Add/Remove Programs to put the server into install mode and then back into execute mode when the installation is finished. However, if the installation routine has any other name, it isn't. Use the change user command line tool to put the server into the proper mode. (Type change user /? for instructions.)
This was first published in June 2003