comm ports

hi, I'm using a wrapper on kernel32 to access a comm port (actually, its a SeaCOM, but from the OS point of view, its just 8 unique COM ports), and whenever I try to do a CreateFile, I get a -1 handle and getlasterror returns a 5 which is the access denied error. however, with the device drivers (again, the specialty SeaCOM card) I got a sample program (in cpp) which connects to the COM1 port correctly and without error. so the card is working fine. which leads me to suspect there might be some sort of system configuration which is stopping c# from opening a port? suggestions? ideas? any would be greatly appreciated :) thanks - Oren