Hi Greg, Hmmmmmm...I have tested it and it works fine for me, at least I get messages telling me I need to set GAINUSE etc.. I won't reiterate Eric, but if you have done a run VLBAUTIL, then I would look at your version of VLBAUTIL and see if VLBACPOL is present. Does INP VLBACPOL or HELP VLBACPOL work? Cheers, Amy