Unable to access most web sites with new Linksys E4200 Router

[#1]

Gutted - I've the exact same issue with an EA4500 I got today - loaded pings want to fragment until I get down to 100mtu.. have tried all sorts of mtu settings in the router settings. Nada. I guess nothing ever came of this post or no one else has had similar ?
Using Cisco connect software it informs me my FTTC connection reaches the 50Mbps downstream that is the max I can get. Well thats just fine and dandy but I cant load any webpages or if they do they are missing content and load very slowly - have created a ppoe connection from my laptop and browsing is all good - back on the Netgear at the mo and again all good..
Its got to be MTU related somehow surely.....arghh.

[#2]

I too have the same issue with an EA4500 set up with a Draytek Vigor 120 ADSL2/2+ modem.  I can access some websites but connections are very slow.  Avast updates, can't access www.google.co.uk can access www.plus.net

[#3]

Sigh. I wish I found this earlier.
I'm now on my second EA4500 - couldn't get either to work. With the frustration I lost motivation... I'm guessing it'll be to late to return it now.
Although I bought it from PC world http://www.pcworld.co.uk/gbuk/cisco-linksys-ea4500-n900-dual-band-wireless-cable-router-13927469-pdt... which clearly states
"For fibre optic broadband such as BT Infinity" I'm not sure if 'not fit for purpose' has a expiry date.
Cisco support is useless on this issue, they have you running around in circles forever.
I guess I'll try a ASUS RT-N66U N900

[#4]

How long ago did you buy it? I'd have a word with Trading Standards if PC World won't give you a refund.