I have several PBO's which I use for primarily watching DVD's. I convert my DVD's to .ISO files and put them on one of three "media servers". in all actuality, they are Windows XP machines with big hard drives and a shared folder for the movies.
originally they were three physical PC's, each dual homed - one NIC was for the normal network so I could remote desktop to control them and copy movies to them, the other NIC was for a dedicated physical 100Mbit network just for the PBO's and "media servers". My main network is a Windows AD domain, but the media servers all belong to the same Windows Workgroup.

After a couple of years, I put together a Windows Hyper-V box and virtualized several systems, including the "media servers", to keep things simple, I just converted their physical disks to VHD's and kept them running XP. same dual homed architecture and everything. about that time, I upgraded the PBO firmwares to P70 R1, and that worked well for another couple of years. Since then I have not made any changes or updates to the PBO's or the "media servers".

within the past few months, the PBO's have been acting a bit weird. sometime I can't even see the Media Workgroup. Sometimes I can see the Workgroup, but when I open it I can't see any servers. Sometimes I can see the Workgroup and servers, but can't see any shares, and sometimes everything would work fine. with in the last month, I can't see any shares at all, if I can see the servers and/or the workgroup.

I've set and reset networking settings and samba on the PBO. I've rebooted both the "Media Servers" and the Hypervisor they're running on.

I need some assistance trying to figure out what's going on and how to fix it.
I really love the PBO's and would hate to have to toss them and buy something else, but since manufacturer tech support doesn't exist, and I can't find any forum posts that share my exact scenario of issues, I've got no idea what to try.

Thanks in advance