Thanks Basj.  I'm now on Beta 3 (strange, it is not available as an "update", have to seperately downoad the file and install).  I use Bitdefender which is a bit more difficult to modify the firewall rules, but I think I've got most of them on the Primary conputer, probably have to do it on the secondaries as well(?).  Can only add the executables as exceptions and I've done 8 of them, maybe too many, but not ure which I really need.  Not much carryover from the Windows firewall rules.  So far I have not encountered the problem, so I think we're on the right track.  Do I need to modify the secondary's rules as well?  Starting to work on them, but would like to know which executables I need to add exceptions for.

It is always the best choice, yes.

On the Primary, for KVM, it would use multi2_64.exe and the Secondary would use multisrv64 and multiplv64.

That said, if you continue to have issues, we are going to ask that you eliminate any 3rd party firewall and work to see that it is solid with Window's native. 

Sean Drohan
Stardock Product Lifecycle Manager

Well, it's been 3 days now without a glitch, so I'd say the problem is solved.  Unfortunately, since I both updated to Beta 3 and made the firewall exceptions I don't know for sure which cured the problem, though I suspect it was the firewall.  I'll let you know if the problem returns, but for now, I'd asy it is solved.  Thank you VERY much for stepping in and helping out and for a fantastic, very usefill application.  Makes life much easier!