Internet keeps disconnecting

[WanchoPiskado]

Hi.
Been using Ubuntu a while now. Really like it. But....

My internet disconnects randomly. My other laptop with Vista installed does not disconnect.

Setup:
Laptop -> wifi repeater -> wifi access point -> DSL modem.

Resetting the DSL modem solves the problem. But this is not an elegant way to solve the problem.

Help!

[WanchoPiskado]

So...i inserted the DNS server from my Vista PC into the IPv4 settings of my Ubuntu PC and I am connected again.

But when i reconnected I got a message saying something about Avahi not liking it.

Not able to get the message again.

[WanchoPiskado]

So.....it's an Ubuntu error. The automatic DHCP does not work. Where can I post this?