internet cutting out

Since installing avast a few weeks ago, i keep losing internet connection. It lasts for a minute or so and is usually shortly after i log in. Can anyone help?

Yes, I got the same problem since update to 10.4.2225.
Still now, update to 10.4.2233, I can’t connect to internet, so I turn off Avast IS to use internet.

Win XP SP3 32bit, I7 760, 8GB RAM