Airport Causing Problems

I installed an airport extreme in my PowerBook G4 at xmas everything is working fine and except I seem to get these messages to shut down the computer for no apparent reason. The computer will be idle and all of a sudden the message appears on the screen. Any suggestions on how to correct this or what can be causing this? The message appears in several languages in the error box.

How does this relate to airport extreme? what languages? what is the exact message? Have you run any disk utilities? Who else is on your extreme, what computers are they using? Printers? more info needed.

sounds like someone is on your network maybe use MacStumbler to check this first.