Randomly can't access webpages

[AnonymousGaijin]

Hey guys, I tried doing a search on this, but couldn't find anything that was similar with a solution to the problem. If it's redundant I apologize.
Here's the situation: I live in an apartment with a roomate, and we have cable running into a router. The router then splits off to a number of devices. All in all i think we have 9 devices connected through switches to the router. Our internet connection is fine, but my problem is this: I can sit down and browse the web for awhile, but then randomly webpages won't display. The message I get is 'can't find the server at (name of website)'. Also if a webpage does actually open, it looks jumbled and the images won't display.
What works:
Our Xboxes, PS3, and Wiis all work fine. It's only the internet on our PCs.
-We have cable, Comcast.
-The router is a WRT54G version 6, firmware 1.02.2
-Cable modem is a 60678EU (Ambit I think? It's doesn't say on the modem itself)
-I have an ethernet cord running out of the router into my room, where it goes into a switch (TRENDnet TXE S50TXE). My XBox, Wii and PC are all connected to the switch.
-Wired connection, we don't use wireless for anything.
-Unsure about ICS
-I'm using Windows XP, roomate uses Vista
-We use Static IPs for all the devices, mine is 192.168.1.107
-Gateway is 192.168.1.1
-I can ping the gateway, the result is sent/received: 4 lost: 0 min/max/avg: 1ms

Thanks in advance for any help, I'd really appreciate getting this annoying problem solved.