From about month ago I get random shutdowns of Comodo Firewall nevertheless if I'm (not) playing games or browsing/watchin' vids. The two executables, cfp.exe and cmdagent.exe, became killed nice and silently and the icon in a systray disappears

There aren't freshly installed apps.
System specs:
[the machine is not clocked]
cpu: amd be-2300 (64bit)
ram: 2x2GB DDR2[ at ]800
mobo: asrock nf7g-hdready (latest bios 2.10)
videodriver: 169.21 (Video 7900GS[ at ]stock)
os: Windows XP SP2 Pro 32bit + 10-15 updates more
account: Administrator
DEP: default option
Defense+ : Disabled
Firewall+ : Safe Mode
Version:
3.0.22.349other security software: Avast 4.8 Home Edition with license key
BSODs: Just one for a year

defective ram module