This has piqued my interest.
I bought a new router about a month ago and since then web surfing has been a bit of a pain. I get a blank page with "Sending request" at the bootm. The after 20 seconds or so it tells me it can't find google.com or whatever. Click again and often it is straight there. The sites I visit most often are my own and this one (so hosted on the same server), Tom's and Google. It happens on them all and on both my PC and Mac, so it's not the machines.
So when I saw Roger's post, I though "maybe...".
I've just been browsing my router. The MTU is not displayed when I have Dynamic IP address selected, but it does allow me to change it if I select PPPoE. The trouble is, it also requires a username and password to do that. I don't have one (assuming it means some sort of service provided by my ISP - I'm way out of my techie depth here). Anyway, the MTU is currently set to 1454 and it expressly warns against changing it unless my ISP says to do so.
So I'm no further forward really, but my IA is definitely a lot more frustrating than it was before my old router went pop.
S