I just wanted to update this. I had the same issue. Building a new(to me) NPVR build, my GBPVR server is ancient. I've encountered many issues since I run Server OS's(2003 x64 Standard on this one) so I'm pretty fluent with the search function.
To be direct: Removing the Hauppauge 418 rules from the devicerules.xml does resolve the issue and allows me to record both analog and digital signals at the same time.