XP SP2 and Internet connectivity

My cable internet connection keeps on disconnecting ever
since I installed SP2.And very strangely I'm getting
connected during morning and afternoon. This issue is
happnening only after 4 PM.My ISP provider is saying that
it is not their fault.

I have the exact same problem. It will drop connection
for the first 5 minutes after a start up. and this is on
a fresh install of xp pro. also windows update will not
work after service pack 2 due to it dropping after
searching for updates. repeatable every time