Nserver silent install inconsistencies

I have created a complete silent install for a Domino 6.5.1 server on W2K. Due to Netegrity playing games I had to regress to 6.0.2 CF2. Now the nserver –silent install no longer works reliably. For instance when you run (nserver -help) as the help in nserver setup suggests the help screen does not appear! Nserver -record works but nserver -playback does not!

The last time I used the silent setup was with 6.0 and that worked without any issue. I have of course reinstalled the operating system a number of times and regression tested the changes but has anybody else seen this issue or could it be specific to this environment?