Web connection problem help needed

looking for some help from orange broadband customers.
The situation is this, I've been trying to sort out a friends broadband connection who happens to be with orange.
His house has 3 pc's and one laptop running windows xp and all of them show this same problem

When he fires up his internet explorer with a default page of ww.google.co.uk, it comes up, when he does a search and clicks on any link the web session loading gets to 4 bars and just hangs there permamnetly, this has happens for all his pc's and laptops.
if it get him to type in some urls only 10% of the urls works with others just hanging.
So far I have done the following
checked the settings on his router which is a Bt 2wire 1800HG
Switched off all firewalls on the pc's and laptops
pointed the router to use opendns servers
checked phone cabling
re-registered DNS with the pc
flushed the routing table
virus scan
replaced the DSL filter
checked the router on another broadband service, my own and it works.
checked his laptop on my ADSl line and it works.

I have tried orange support who just instanly refer us to BT and then BT refer us to Orange.
His broadband speed is ~7900kbs
The problems started mid January, nothing was done on the pc's for probable cause.

So any further Ideas on troubleshooting would be appreciated

Been over to a website called www.orangeproblems.co.uk, didn't know orange broadband(bought over from wannadoo) were that bad that someone has created a dedicated website to it.

Anyway looking through the forums there is some MTU size issues with orange and it may solve my friends problem. I let you know how it goes, there been some viewers but no replies so some people are interested on the results or have similar issues.

sounds like he's been migrated to LLU (if his connection has been ok before this) & the MTU is more than likely the problem. as he's not using an orange router make sure the router doesn't have it's own MTU settings page in the config pages, i know one or two of them have, as DRTCP won't fix this. 1492 usually works, if not, try working up from around 1400. Orange CS should be able to tell him if he's been switched to LLU, or you can tell by the upstream speed (288ish is LLU). If it's IPStream it's unlikely to be the MTU,so i'd try another router if possible if this is the case (upstream should be 400+ if it's IPStream)

yep that was the problem, set his MTU to 1458 and it all burst into life, also changed his RWIN from the default.

How Orange support couldn't tell him that I don't know as they must have had plenty of calls about this particular problem, but that's what happens when you outsource your call centre to Indian.

50p a min they charge for their support line, for the quality of the call service I'd class it as a phone scam by orange and oftel need to be involved.

How do you guys put up with it, you deserve sainthoods in my opinion.

Told him to move to another ISP once his contract was up, as there are better ones out there such as BE, Zen.