Yep. I agree. I've seen this problem a few times.
If this is how he's connecting it's a fairly easy fix:
From:
http://www.roaringpenguin.com/pppoe/how-to-connect.txt
I) I can browse some web sites just fine, but others stall forever.
There is probably a buggy router or firewall between you and the Web server.
One possible workaround: In /etc/ppp/pppoe.conf, find the line which reads:
CLAMPMSS=1412
Try lowering the 1412 until it works (go down in steps of 100 or so.) Each
time you lower the value, you have to restart your connection like this:
adsl-stop; adsl-start
This should work around buggy routers which do not support Path MTU discovery.