Logon scripts

We just purchased a Helpdesk software package and installed it on an NT 4.0 server. I created a logon script (start \\helpdesk\trackit\audit32.exe) and saved it in winnt\system32\repl\import\scripts on the PDC so that when users logs on, the audit application will launch. However, only those with administrator rights will have the script execute. The other users logon attempt will not execute the script. On top of that, the PDC will not even let them logon to the domain. I think I am missing something. Any ideas? Thanks.