Losing wireless connectiom.

[Fidelio]

Hi,
I have one desktop PC (Ubuntu 9.04) in my house which is wired to my router by ethernet. My wife's laptop (Ubuntu 9.10) and my netbook (Lubuntu 10.4 beta) seem to lose the wifi connection if the desktop PC is rebooted. Why might that happen, then? And what can be done?
I'm guessing it has to do with addresses. And stuff.
Many thanks,
You're great, you are
F

[Psumi]

A.) Is the wireless router your Desktop? (IE: iMac?)

B.) Is your desktop computer connecting the internet through it to the wireless router?

[Fidelio]

Hi,
Thanks. It's B. The desktop connects via an ethernet cable to my wireless router which is a BT Voyager 2091. It's becomimg a bit of a pain. Sometimes rebooting the router and/or the affected laptop fixes it. Sometimes it doesn't.