Virus database update error thru proxy


I have CIS installed on my second PC.
It connected to inernet via FreeProxy software (HTTP proxy) installed on my main PC, and i have no problem with updating CIS , but virus database not working. CIS just suggests me to check my connection and try again later. Connection is fine coz other sofware (browsers, updaters, etc…) works properly with it

Is that known issue with the virus database update through HTTP proxy? Any solutions?

PS. Sorry for terrible English, it’s not my native. (R)

I’ve the same problem and I’m using actually the latest version: 3.5.57173.439
I’m using W VISTA and I’m unable to update AV database.