Hi Rob, yes its Mark the Network Eng from the girls school!
Perhaps you could send me some screenshots of your setup on the NPS/Meru on how to do
I'd take a look at Munki to add some extra tie in for your software updates - munki - Managed software installation for OS X - Google Project Hostingjamesfed Today, 08:57 PM
Not sure if it will help the underlying issue but there are hotfixes for gpmc related DNS issues:
Could it be that they were running Windows XP Embedded? Some versions of that are going to be supported until 20-bloomin'-19!biz Today, 08:07 PM