Wifi switching off on new router

I have a 2006 white macbook. I recently got a new router which is an "N" router. For some reason now my macbook disconnects every eight or so minutes from the internet even the airport indicator shows that it is still connected but it is not. I then have to turn it off and on again airport) to get it to carry on working online. What can I do to make sure it stops disconnecting. It did this before with the previous normal router except it did it about once a month. Thanks