PPPoE won't work with client routers

RouterOS General
1

Very odd problem:

  1. Windows XP client: connects well and browse the internet OK with PPPoE server.
  2. When I configure a router (like WRT54G), it connects, gets IP address, I can browse to Google but nothing else. I can ping any website in the world, but if I try to browse it will stay on "Waiting for http://www.site.com… except for Google.

Weird thing, it works perfectly when XP/Vista/7 direct connection to PPPoE.

What should I do? Dns is OK also.

PPP profile print:

1   name="Residential" local-address=10.5.40.1 remote-address=Residential_pool use-compression=no use-vj-compression=no use-encryption=no 
     only-one=default change-tcp-mss=no dns-server=10.5.40.1
2

Kinda sorted this by myself:
At least for WRT54G, you have to change MAX MRU/MTU to 1492 on the Mikrotik END (PPPoE Servers).
It wasnt working when trying to change WRT54G MTU.

Cheers