Whoo...update time. Yep, still having the problem. Going to go connect to my friend's network again tomorrow to see if that will fix it again, and try to keep an eye on what, if anything, changes like you suggested Doc.
Went out and spent the $26 on a 6 ft (about 1.5 meters for you crazy metric Europeans :-) crossover cable today; yes, they are way overpriced at BestBuy, but my only other option was ordering online and waiting 1-2 weeks. Doesn't matter, it didn't work anyway, so I'm taking it back tomorrow. I hooked the two machines up with the UTP cable, and the exact same problem. They could both join the game room, but the XP machine only showed itself loading.
Let's see... I also checked on that lease time thing Phoenix, because my router only lets you set lease time for maximum of one day. But I released and renewed the IP on both computers to refresh the lease, but no help. Then I deleted all of my protocols and added them back one by one trying each time. No help there. Also, doesn't matter who hosts; always EXACT same problem; ME computer shows both loading; XP computer shows only itself.
So, aside from trying it on my friends network again tomorrow, I think I've tried everything anyone has suggested on this board. Did I miss anything? Any other suggestions? I'll update again tomorrow when I get back with results from hooking up to friend's network. Thanks again.