Not sure where to ask this, so I'll try here as it's probably the best fit

Every now and then, a random host (all XP32) loses the ability to contact a random BOINC project, it just gets "project temporarily unavailable". It looks as if the project is down, but it isn't as I can still see it in a browser on that host, and other hosts hanging off the same network switch still communicate without problems. If I detach I can't then reattach

I've checked all the local BOINC settings, no firewalls/antivirus/proxies in use (apart from router firewall), hosts file OK, can ping/tracert the project from the host etc etc. The project used to run fine, but just suddenly dies

Fired up YAFU again recently, all of the hosts that I run it on connect and get work fine. But one random one won't. In the past I've seen BURP and Pirates die in the same way. And others that I can't remember.

I'd usually blame this on dodgy firewalls/av/routers etc, but these are clean XP installs with no junkware installed, and the project used to run fine until Sudden Death Syndrome hits it.

Any ideas? A thorough google just comes up with the usual stuff about firewalls, proxies and the like Oh, these are all BOINC 5.10.45 - Don't want to downgrade to a newer dumbed-down version thank you very much