After days of reading, trying different things, I'm out of things to try.
To make a long story short, I have 2 ADSL lines, 1 static IP and another pppeo-client one.
If I link a laptop directly to the routers, all sites work no problem.
If I link the laptop through 2 RBs (only masquerade out to Internet) and setup only one connection as gateway then some sites does not work or is very unreliable, but if I setup the pppoe-client as gateway, then all works fine. I removed all filter and mangle rules but same problem.
I thought it migtht be MTU/MSS so tested the static to give max MTU of 1454 (which I changed in config) and added mangle change-mss rule to 1414 (MTU-40). But the laptop connected directly had a MTU of 1500, so I don't think it's that.
Then I thought it's maybe TTL as there are over 30 hops from where I am, so added a change-ttl rule to make it 250 or 0, no difference.
www.cnn.com sometimes give problems, but www.itv-f1.com is very consistent in giving problems. www.itv-f1.com just wouldn't work through the MT but directly connected it's just fine, orif I use the pppoe-client connection, then all is fine.
Any advice here? I'm out of ideas.
Ekkas