Anyone handy with wireless connections here? We're having some problems with a laptop that is losing its connection at random intervals. Rebooting our router and wireless usually fix it of course but what the root problem is, is unknown

For instance, an hour ago I had the laptop in my lap, two meters away from the access point, and it simply could not find it. But my psp could! The laptop did find two other access points though (our neighbours I assume), but couldn't connect to either.
As far as I know, my sis have not been tampering with any settings at all, and after unplugging the whole router for a bit, it worked again. For 10 minutes, then it died again. I'm at a loss here :S The lights for "wireless" and "internet" are blinking in weird patterns for no obvious reason. We're currently running without passwords but I can't remember why :lol Not sure if that could mean dropped connections at random, for random devices though.
While writing this, it seems to have fixed itself magically for the time being. Still, any ideas? Fixing another WEP is probably a good idea either way but it sure is a hassle to get running (for some reason, it's not possible to make an unsecured network secured again without changing the settings via a "hardline" connection).