Can Skype; can't browse

Greetings from West Africa!

I'm trying to set up a new wireless network at home.

Specs:
Dell X1 laptop
Thomson SpeedTouch 530 v6 ADSL modem
Phoebe wireless router

1.
With the modem connected directly to the laptop via ethernet, everything's great. So the modem works OK.

2.
With the modem connected to the router, I lose Internet access ... although I can Skype, strangely enough.

3. The wireless connection between the laptop and router is excellent. So the router is OK.

So what's going wrong between the router and the modem?

Any suggestions appreciated.

Ria