Firewall blocks incoming connections (V3.8.65951.477 X32)

Firewall erroneously blocks incoming connections for server when program update is available

Seems pretty weird, but it’s happened at least the last 2-3 times there’s been a program update to install… When the update for Comodo becomes available, I can no longer connect to my computer remotely (even though I have a rule specifically allowing a particular port). It logs the blocked events (as “windows operating system”), but won’t let me connect until I run the available update, and reboot. Of course, I don’t notice that it’s broken (or that there’s an update available) until I’m away from my computer and can’t do anything about it.
CPU athlon 64 X2
OS: Vista SP1, 32bit
mode: (custom, D+ is disabled – incidentally, I was never able to get it to accept the incoming connections in “safe” mode)
UAC disabled