There's nowhere near enough information here to be able to provide analysis that would lead to any specific solutions. The only advice I can put forward is to look at differences between the machines. Printer queues, Plot queues, installed version of NX, hardware, operating system.
I did find a solution. It involved deleting all folders below C:\Documents and Settings\username\My Documents\print_submit. Apparently there is lock file here that prevents plotting to a file.
I haven't figured out how to permanently remove the lock file though
