Pascall
To help you further I think we need to see what is in @error (and @serror) after the USE command is issued
We do this sort of thing, so I know it should work.

Lets use your simple script as a testbed.

like

code:
  
If InGroup ("OGG-Projectleiders")
   $ = AddPrinterConnection ("\\WH-SQL\HP5PROJ")
   $ = AddPrinterConnection ("\\MSNSRV\HP8000")
   $ = AddPrinterConnection ("\\WH-SQL\HP4VTEK")
   $ = setdefaultprinter("\\WH-SQL\HP5PROJ")
   use lpt1: /d
   use lpt1: "\\MSNSRV\HPLJ5000"
   ? "ERROR  IS @ERROR"
   ? "SERROR IS @SERROR"
   endif

Tell us what you get...

Mark