I'd download Firefox as mentioned. I use it but for your case it could at least narrow down the issue a bit. If it happens on firefox then it obviously is not a problem with IE. You'll probably stay with firefox for what it's worth and that is a good thing. Tabs, nice little popup blocker, download manager and not such a big target sign on it from the skiddies.
If it's not IE then you might want to look at your connection, either locally with a NAT router, or possibly an ISP problem.