Why can't my new router access internet?

Hello!

I have ISP from a swedish company, telia. I recently upgraded from 0.25Mbit to 2Mbit. 2Mbit is the absolute maximum that we can have since we live at the countryside.

My hardware used to be a adsl-modem from Zyxel (provided from telia). From this modem I connected a router D-Link DI-604. After upgrade everything worked fine for 3-4 days. But after that I constantly lost the internetconnection after 3-4 minutes.
But if I used the modem direct into a computer it worked fine.

I got the idea to upgrade the firmware for the router, but after that the router just stop responding totally.

I decided then to buy a new router (with a modem inside) D-Link DI-624 ADSL2+. This new router seems to work fine for the LAN, but it refuse to be able to connect to internet.

I called telia, and they said that it looks like it mange to get a ip but loose it at once, they also said that they get broken packages back indicating that somethin is wrong. We also tried the old original modem from telia and it works fine, no broken packages at all.

In this new router it looks like I have a lot of parameters to play around with so my hope is that this is a config thing.

So if any one out there have any idea please let me know.

Best regards
Fredrik