problem with automatic connections to remote servers

Well,

I'm generally fine with computers, but I have a problem with my laptop that has me stumped.

Whenever I try to connect to what I guess are remote servers automatically my computer comes up with various incarnations of what is essentially the same error message "connection timed out" "connection may be down or blocked by your firewall settings" etc.

This happens when I try to connect to the Itunes store and just now when I tried to run (after successfully installing) the GameTap updater. Basically I can download things fine, but any automatic update or connection to a game through a client etc fails. It started several months ago and I can't remember what changed at the time, but I may have downloaded an update to windows. I have tried reinstalling software such as Itunes to no avail (though thankfully it works fine otherwise).

This has been the case with both wireless and directly plugged in DSL. My laptop is cheap and about a year old, in other words not great, but it has no other persistent problems.

I have put security settings as low as they go and shut off the Vista firewall.

Thanks for any insight.