Arrrgh, I just tried everything described in the first post over again, and no results.
So I suppose it's either a Firewall issue, or something I haven't been educated on yet. Aside from turning off Windows Firewall, I have no idea what else could be on my computer stopping it (the router, maybe?), but this has never been an issue with anything else before.
Which is a shame, because I'm heading on a trip for the weekend and won't have my shiny new 120zune.
I'll have access to a laptop, though, and will check these boards as much as possible. I appreciate the input so far, if anyone has any idea, it'd really make my weekend!