Here's the details:
1) Small "about:blank" window opens when opening a new web page.
2) After closing the window, another pops up saying: "this page has an unspecified security risk, would you like to continue?" This can be closed with several clicks on either yes or no.
3)After that window closes, a script error wndow pops up.
Although this happens most of the time, occasionaly it can be closed with just one click. Furthermore, explorer is freezing up after about an hour or so. This is only remedied by shutting the PC down manually and restarting. Maybe the issues are related?