Problem accessing Tees.ac.uk (Teesside university)

[#1]

Haha - see I said it was satb in the dark!! 

[#2]

Mayfly, the only difference you should see with the different gateways is just different routing inside PN's network hops. If its at a different data centre slightly different hops depending on what peering is used :).
But with tees.co.uk the issue is resolving around inside their network it seems :). And depending on dns propagation the problem may vary between pc to pc and isp to isp :(. PN is actually very fast (usually) with dns propagation I've seen domains go live from daily/godaddy to live on websevers within 15 mins :).

[#3]

Looking at your account, it has nothing from a network configuration level that would be any different to that of the majority of residential customers.
The observation I can see that has not been asked, relates to MTU values (which can also provide an explanation on why 3G works but DSL doesn't).
http://www.kitz.co.uk/adsl/MTU2.htm
Please follow the section referenced "Working out your maximum MTU".

[#4]

Thanks for continued suggestions.
Trying to cover some of those - I get the same issue with www.tees.ac.uk as without the www.
I have looked at the MTU values before but the referenced artice was an interesting practical description of how to calculte this - for the record, for my connection, it comes out at 1393 at the moment. my OS is windows 7 so RWIN is dynamic.
Sadly having set 1393 on the router, no apparent difference and still no acess to Teesside Uni.
Will see if IT support at the uni can make any sense of it tomorrow.
Jim

[#5]

Just to let you know - while there is no logical reason I can think off, swapped out my router with a new one and can now access the site no problem.
Thanks to those who contributed suggestions.
Jim