I take your point about WinME no longer being supported, but bear in mind that Windows Automatic Updates supplies updates for all Microsoft applications as well, even if the operating system itself is no longer supported.
But since your automatic updates is disabled I accept of course that it can't possibly be that that's causing the mysterious internet activity on your PC.
You may want to have your PC checked out for any possible malware that's running on it. This is usually done by installing something like "HijackThis", running it, then submitting it's report to the forum to be analysed. I can't analyse it as it requires someone who is experienced in reading such reports.
You can get HijackThis here: http://free.antivirus.com/hijackthis/