I have Citrix XPa Server with a modem configured on COM1. My problem is sometimes Users can not connect to the server using the Modem, when quering the modem I get a message "port already opened", even though I have no programs running that could be using that port, the only solution is to reboot the server and then it works OK.

Anyone seen this problem, and how to find out which program/service using the COM port without having to restart the Server?.

Thanks,