friggin' network

I am seriously about to pull my hair out. Or scream. Or both! I can't get my wireless network working, and in addition to being extremely frustrating, it's quite possibly going to make me crazy. I don't know what went wrong!

Set up this network in January and it works fine for Internet. Only Internet. Both computers are running XP with Service Pack 2, but for some reason, the network will only work to share the DSL connection and nothing else. We've got a Linksys WRT54G, which I've recently been told is great for Internet sharing but difficult for networking.

Great.

I have tried everything. Tried it with all the firewalls off (that was scary), tried changing some of the settings (the ones that didn't require arcane computer knowledge), even tried eschewing Linksys software all together and using Windows Zero Configuration (that sucked!).

Here's the weird part. Both computers are on the same workgroup (I know this because I've checked about a bazillion times). So, when I go to My Network Places, you'd think I could access them... but I can't! @#&%!

From the kids' computer (Killjoy), I click on "view workgroup computers" and I see Killjoy. Not our computer Stewie, just Killjoy. All alone in the workgroup.

From my computer (Stewie), I click on "view workgroup computers", and there Stewie, all alone and lonesome. What the heck!? Which is actually a step up from before when the computer would think for a LONG time and then claim that I didn't have permission to access that network resource. Like hell I don't! I AM the administrator!

SO....please help!! Any ideas would actually be fabulous. I'm at the end of my rope!