the owl and the olive tree

I have my new netbook! I decided to get an Asus eeePC, mostly because I've been quite happy with the one I borrowed from ceph, and it seemed smart to go with a known good. As an added bonus, they had one in pink!

The one I got isn't quite this one, but it's a close cousin. Since it's cute and pink, I had to name it Pinkie Pie, after the My Little Pony: Friendship is Magic character.

Anyway! This means that I now have A Computer Of My Very Own (not a work computer, not a borrowed computer, but My Very Own) for the first time in... weeks and weeks and weeks. Today I expect to spend mostly getting this set up to my preferences, fiddling with settings, downloading stuff, etc. But tomorrow I'll get to work catching up.

Yay!

So my shiny new laptop is very shiny and works beautifully, except for one thing -- it gets weird about the Internet sometimes.

There are three symptoms:

1. Not infrequently -- once or twice an evening, usually -- it drops the connection for some reason. This means that everything that requires the Internet (Firefox, AIM, Final Fantasy XI, etc), plus everything that require the local network (mapped drives, remote desktop, etc) all die at once. This can be fixed pretty quickly by repairing the connection, but it's annoying.
2. Also not infrequently (at least once and sometimes many times per evening), programs that involve streaming a lot of information over the Internet/network (primarily Final Fantasy XI and remote access to my desktop) will time out. No other Internet/network services are affected. This usually fixes itself between two and five minutes, allowing me to reconnect, without input from me, but is also annoying.
3. Sometimes, usually when coming out of hibernation or suspend, or more rarely while I'm actively using the computer, the connection will switch from 'local and Internet' to 'local access only.' This means that access over the local network is fine, but the Internet at large isn't available. Nothing seems to fix this besides rebooting my laptop, at which point it's fine.

Specs: It's a Dell laptop with Windows Vista Home Premium. The boy also has a Dell laptop (slightly different specs) with Windows Vista Home Premium, and he doesn't have these issues -- once in a while his connection drops, but not as often as mine, and the lag/timeout doesn't happen for him at all.

I have already disabled auto-tuning, which helped but not enough. I did the Microsoft Network Connectivity Testing thing, and it says that everything's working fine except Universal Plug and Play, which, I don't know whether that would be causing these symptoms or how to fix it if so. Otherwise, I'm puzzled, since the boy's laptop with very similar specs works just fine. I can't find anything in Event Log about it, either, although I suppose I might be looking for the wrong thing.

Anyone have any ideas what could be causing this kind of problem? Or an idea for a diagnostic I could use to figure it out? (It happens often enough that I could easily run a diagnostic until the problem appears, if that would help; I just don't know what to run.) It's really super annoying.

(Anyone who gives a response such as "Go back to XP" or "Switch to Linux" or "Switch to Mac" or whatever -- which are designed to make you feel superior rather than to help me -- will be roundly mocked and then soundly ignored.)