mostiscar, as you have DSL and router, the normal way of using PPPoE is for modem to logon (or if you have modem / router in one unit) that does the PPPoE stuff to keep you online, logged in and so on.
The DAP 1160 function is mostly as a access point. If you are going to use it the way I think you want to, then you probably need to use the DSL modem as a bridge and then plug the DAP 1160 directly to the modem.
The router is probably preventing the PPPoE from working they way you are setup at the moment.
If the hardware you have for DSL was provided to you from your ISP I am sure the PPPoE things should be in those units and you can get it working that way instead of having to configure the DAP 1160 for that function.
If you can, call your DSL provider and talk to them. They should be able to get you on the right path to solving your current problem.