Connection Refused on 64 bit server

After adding NSCLIENT.EXE to DEP, I was able to get the service running on a 64 bit server (2003 w SP2). All I get from the Nagios web site is connection refused. I am using the exact same password that works properly on all the 32 bit servers. As a metter of fact, the ONLY thing that is different is, the OS is 64 bit. Does anyone have an idea how I can fix this issue?

I need an answer ASAP, my manager plans to upgrade all servers to 64 bit OS by the end of the month (August 2007).