Network Shield in Avast 4.6.603 build blocks NNTP downloads?

I’m using the 4.6.603 build of avast on a Dell Optiplex GX1, Pentium III 45mhz, running Windows XP, and I’m experiencing a problem.

Whenever I go to newsgroups, I get the little scan icon pop up in the taskbar which tells me avast is ready to scan any downloads I make. But here’s what happens when I download: nothing. Whenever I go to download anything from newsgroups, it freezes. And all other functions on my PC slow down as well. I thought I’d go into Task Manager to see if there was anything in there that would give me an idea of what was going on, and I saw that CPU usage was pegged at 100%. I actually had to disable the avast program to finish my download and get the CPU usage down to normal. Is this an indicator of some kind of bug? Because none of this was happening before, and I’ve been using avast for a year and a half.

Newsgroup scanning (NNTP) is new with this release of Avast. You can (if you wish) disable NNTP scanning in the Internet Mail provider. If you wish to disable it completely and still leave mail scanning active then you can change the NNTP port in the provider to some fictitious number like 11119.

However, I must comment that, while I have seen some small impact to other CPU intensive activities during NNTP scanning on my (older) Dell machine it has not been pegged at 100%.

Could you please try the NNTP scanner patch, as described here: http://forum.avast.com/index.php?topic=11400.msg96848#msg96848

thanks
Vlk