I've had weird stuff like that happen to me in the past. I would guess the router is the issue. In my experience Belkin makes nothing but crap for routers. A new wireless router is probably the cheapest thing to replace if you buy during a decent sale. The newer models don't seem to have the odd problems of earlier ones. I'm using a Linksys WRT54GS at home now and hasn't has a hiccup since I got it about 3 months ago. I also have a Buffalo WYR-G54 for travel use. Seems to work very well and has a metal case. Recent Netgear routers I've used are stable, but I think the range kind-of sucks. I'd stay away from Belkin and D-Link, but that's just my opinion.

There was a thread about wireless gear a while back, but it has some good info about brand experience. Here