Hi Sebastian:
Thanks for your reply. But actually, the upgrade is from DNN4.3.4 to 4.5.3. And I believe there have been numerous posts about problems with upgrades to DNN 4.5.x where, although the site appears to run correctly in browser mode, in admin and host modes, changes do not get kept and one can't get out of the edit page of the module. All that happens is that the editor goes from edit to view. And one can't log out. You have to close the browser instance.
I have attempted to up[grade 3 times without success. Before I thought maybe I was having FTP problems. But then my hosting service tried to upgrade as well and they also failed. I have hired another party to try and they have been unsuccessful.
Now maybe it is because I have some non standard modules in my site. But I get no error messages during the upgrade. It just doesn't work. I was hoping maybe someone, that experienced similar problems, like those in this thread for example, might have come up with a solution.
Just for your info, I have also tested DNN 4.5.3 locally on an XP home machine with Visual Web Developer and found I had some similar problems if I disallowed Friendly URLs. But maybe that has something to do with my running environment.
Regards
Ron