Internet Connection Sharing wierdness.

[dread]

I finally got my home peer-to-peer network working and everything seems to be running well... except that my PC constantly keeps dialing up the internet.
We have two identical PC's linked with my housemates PC acting as the ICS host using a 56k dialup modem. But for some reason I can't stop my PC invoking a dialup connection when it boots up. If I manually disconnect it just connects again after a couple of minutes. This is becoming rather annoying as we don't want the phone line tied up all the time and messes with our network gaming antics. I really don't want to leave my PC off all the time either. I know its my PC because when its off the ICS host (my housemates PC) does not dial up.
This did not happen for the first few days of having the network up and running so I thought that there must have been some software trying to get an internet connection. So I have checked all the obvious stuff like Windows Auto-update and Norton AV's live update which are both disabled. I also ran Ad-Aware 6 to check for spyware, but it just found one dataminer reg key which I have removed. Norton AV finds no viruses either.
I can't see any other programs that could be causing this but could I have missed something? Is the an ICS/network setting that needs changing? Anything else I should check?

 

[dread]

Looks like I have fixed it

Just in case anyone is interested...

After installing the latest version of Ad-aware and updating it I found this key...

SOFTWARE\Microsoft\Internet Explorer\Extensions\{c95fe080-8f5d-11d2-a20b-00aa003c157a}

A search on google tells me it's the famous 'Alexa' key.

If you use the 'Related Links' feature of IE, it will contact the Alexa (an Amazon company!) servers to obtain information about other web pages, which might be, er, related, open an Explorer Bar, and display those (plus adverts and whatnot).
Transmited is the complete url of your search result to both "msn.com" and "alexa.com". In some cases this could contain sensitive information such as username, password, session id, search string, "secret paths", and more. The vulnerability has been confirmed for Internet Explorer 6 on Windows 2000 and Windows XP with all Service Packs and hotfixes.

Microsoft say its not spyware, but most (including myself) would say it was. Gits.

Removing this key has fixed the problem, but I'm not sure why to be honest. I don't use that feature and just starting windows (without running IE) causing it to dial up.

Oh well.