Using bridged mode works but pppoe doesn't work

First of all, I am new to the forums, and really don't know if i can ask this question because it might not be related to W7.( I posted it here becase at anytime this forum is visited by over 10000 people) Anyways:
I have a router tp link td 8840t.
It is a small modem which i got from my isp and is good enough for my needs. When i use bridged mode and connect using broadband connection of W7 internet is awesome.
However if I use pppoeInternet becomes very choppy.
Now I was wandering why could this be? I experimented with various dns' from google ublic to opendns to my isp's dns but no matter what I try it's always choppy. So I was wondering if any of you guys or gals from this forum could help me?

To my knowledge ADSL 2 (+ or whatever) does not use PPPoE for authentication. The authentication for connecting to your ISPs network, allowing you internet access, is done by the modem/router serial # or the MAC address. So trying to use PPPoE is why you aren't getting any INet access. Reset the modem/router box back to factory specs. The reason you are getting good INet access with it set to Bridge Mode is it is then authenticating with your ISP but your Win 7 computer is now getting a Public IP address, not a good thing to do. Bridge mode basically make is just a modem so you can install your own router and the add on router would be set to Dynamic IP Address, Again No PPPoE. So set the modem router to Dynamic and see what happens.

It's not that I don't get any Inet at all. I get it a lot speed is fine but it is choppy. Downloading using IDM works perfectly.
Flash, Javascript and other stuff doesn't work and it often doesn't load the page. PPPoE worked fine on my previous router. It sometimes tells me it's a DNS problem but changing DNS or even changing TCP MTU or TCP MSS doesn't work.
Should i put ipconfig /all log or something?
Also flush dns doesn't work.
Setting it to Dynamic can't work because to connect you need some kind of authentication.