I still have not been able to get this working.
Here is a step by step of what I've done:
I started off by making the group in active directory, illustrated below:

Then, I added myself to the group, and set it as the primary group, illustrated below:


Then I ran a simple enumgroup($index) script on my account.
It returned Domain Users as my group.

I've tried various incarnations of this script trying to get it working:
Code:
     addprinterconnection("\\mcsrv\LongCSR")
IF INGROUP('LONGUP') 
    setdefaultprinter('\\mcsrv\LONGCSR')
ELSE
? 'long marker (I used a 200 character marker to test)'

That actual script is a bit longer than that, and it includes all of the printer connections, then runs through the script to determine default printer.

I am not sure what I am doing wrong, and any assistance would be appreciated.