is it true that the update of avast is always only 3 or 5 kb small/big?
and that i just need some seconds although i just have 56k-dial-up-modem?
im confused because all others AV i had needed 1,8mb to update…
Yes, a typical size of a virus DB update is between 3-30KB.
Some more info here: http://www.avast.com/eng/avast_4_home.html#4
markus0r - I am also on dial-up and I can assure you that it only takes seconds for a normal update. I do not think it’s taken more than a minute even for program updates! 
How can the updates be so small? compared to AV’s updates that are 1.8mb?
A clever algorithm is used to transfer only the small parts that have really changed between the updates (and even those are additionally compressed, of course).
Cool 
well. very interesting
if the update is so small, i can just say: wohoo, nice work, dear programmers, avast! roxx the world :))