I don't know how widespread it is but for the last couple of days some
people (me included) have started seeing problems when using F-PROT
It appears that the latest definition updates are causing the program
to hold on to allocated memory, so the machines gradually grind to a
halt due to lack of available resources.
If you use F-PROT (both XP and Vista machines seem to have the
problem) then you might like to keep an eye on the amount of memory
used by FPAVServer. NB Running an AV scan can result is a loss of
200-300 MB of memory, so reboot afterwards..
The From address is valid