I haven't heard back from you in a while so I thought I'd check in again.
I've been trying the IPconfig release & renew method, and it actually does work sometimes, though not all times. When it does work, it seems like it takes a while for some apps to pick up on the fact that there's an internet connection again. ICQ comes back online almost immediately, but MSN and Internet Explorer don't work for about another 2-3 minutes after that. Either way, it does work... sometimes. Other times, not at all. Again, it seems to work just as often regardless of whether I'm wired/ not wired.
My roomate (computer Akiva) is out of town again right now, and I'm still losing my connection, although I she did leave her computer on. My connection was down right before I wrote this post, and I checked eventvwr. The only error it seemed to have since I last used the internet last night was one from W32Time saying it could not sync the time.
One other thing: My above-mentioned roomate is actually moving out in the next 1-2 weeks, so when she does, it will just be me in the house for about a month, which should settle the issue of whether it's a conflict with her computer or not.
Any further thoughts?