POST error: I/O conflict ports: 2f8

While using an application the screen went black. At reboot I received an error during POST: Memory Test failed. I reshuffled the memory chips and that error went away. Then another error appeared: Conflict I/O ports: 2f8 and POST stopped. I pressed F1 to continue and the computer booted OK. But every time I turn the pc on or restart, I get that Conflict error and the POST stops.
I uninstalled the com ports twice, uninstalled and removed all traces of the application that was running when the problems started, reinstalled Win2k, downloaded and installed Win2k Service Pack2, still the Conflict error appears during POST and POST stops. HELP!!!