Right Click Shell Scan Doesnt work 2nd Time

I can successfully right click and click ‘Scan with Comodo Antivirus’, but if I do it another time it doesn’t work. Its like the command got lost or something. If I restart, the first time will work again but none after that. I have had to do a clean reinstall of my OS and it happens before and after the reinstall. Anyone else have this problem?

WinXP SP3
Comodo Internet Security: 6.3.302093.2976

Doesn’t work at all for me on Win7-64.

If I try to scan a file using this option, it causes Explorer to hang, requiring me to kill it and launch a new one. Using AV from CIS 6.3.294583.2937.

Funny thing is, works fine when I dual boot into XP on the same PC and run it there.