Can't lookup or submit files. CFP 3.0.25, Vista SP1, x32

Almost every time I try looking up files to Comodo the online lookup reports the result “Error”. No matter if I try looking up 1 file, 10 files or 100 files the result almost everytime is the same. Only one or another file from time to time is reported as “safe” or “unknown”. I guess I approxymately five days of a hundred days get a file reported as “safe” or “unknown”. If I try submitting some suspicious files I often get the same result “error”.
The submitting process also very often goes very slowly and the traffic occupies 100 % or near 100 % with svchost.exe

This problem has appeared since I started using CFP in february 2007. I stopped using it, removed CFP and had a service which reinstalled my PC. Tried CFP again from December 2007 but the problems still appear.

The number of “My pending files” waiting for an review is increasing everytime I turn my PC on and accesses the internet for a while. Until two months ago the number of pending files could increase by a couple of hundred or thousands each time. It had reached 130 000 files, almost doubling each week, when I was in a hurry, shutting down the PC (laptop) by pressing power off. Next time I turned on the PC there was no “Pending files” and since then the number of files increases much slower than earlier.
Now it only increases with a few files each time but it seems escalating. I now got 124 files waiting for a review. In a week I guess I may have about 170.

Mostly CFP reports these pending files as “Modified”. Only very few of them are reported as “new”. Even if I update AVG the virusupdatefile may be reported as “modified” rather than “new”.

Network defense is in Safe mode.
Proactive defense is in Clean PC mode.

I use AVG 8 Free and Windows Defender. Windows Firewall is turned Off. I also got CCleaner.

Firewall events reports:
Approximately every 30 minutes ( or to be accurately: 28 minutes and 33 seconds between each event) the Firewall blocks an event regarding Windows OS.
(Application: Windows operating system, Action: Blocked, Protocol: UDP, Port: (different)).