DI-524 cant browse internet

I seem to be having trouble with my computer connecting wirelessly to my router. before I go into any issue, here are the specs:

router: DI-524 ver D1, firmware version 4.03

PC: OS: Windows XP pro
NIC: Linksys wireless-g PCI adapter. Model: WMP54G
Connection: Very good
security on router: None

My issue is that I can connect to the router, yet I cant seem to be able to browse the internet. I was previously having the issue of my connection being dropped every 15 to 30 seconds or so, but I fixed that by changing the Wireless channel to 1 (not sure if it still does it though, maybe it does but much less). Except for that change, every other setting in the router is factory default (yes, I already tried resetting the router). The connection is ONLY from my computer to the router because (as we speak) my roomate's computer CAN connect to the internet via a LAN cable to the router. So it really is ONLY the wireless, not sure if its only MY computer though.

I already tried downloading and installing Windsockxpfix on my computer, did not work. I already tried turning off the modem (which is a cable modem btw), still nothing changed... Any suggestions? Ideas? I really need some help on this one...

P.S. before someone starts posting about router security, I know I have to do it, I just want to establish a connection before I go any further... thanks!