Since upgrading to 4.8 i got a strange problem in one of my portals.

changing back to 4.7 let it disapear again. i have one page in this portal who has around 5 listx modules on it. these modules make some database queries and output it to the page. Since the update the browsers shos the titel in the explorer and then after some seconds a internet explorer popup show page http://something/default.aspx can not be opened. Request canceled.

What i tried so far to resolve:

1. deleted cache on both server and client
2. tried several clients on different machines
3. tried directly on the server
4. checked all the modules for invalid sql queries )even they were working on 4.7)
5. disabled all modules for non registered users
6. disabled cache on server
7. Disabled Firewall on server
8. checked that there are non files called from a third machine (maybe DNS error)
9 change caching from Memory to Harddisk and vice versa

All that doesn't bring any change.

if i call the page and then after the popup appears, if i click on the popup and then push the back button of the browser, the page gets displayed without any error.

Does anyone has any idea of what to do?