If you are using the QlikView Webserver you do not use http://localhost/QvAJAXZfc/AccessPointSettings.aspx
it should be http://localhost:4750/qvws.asmx
The http://localhost/QvAJAXZfc/AccessPointSettings.aspx is for IIS.
Try changing that and get it a try
I could solve the problem. I'm really happy :-)
It seems that I couldn't open any aspx pages due to incorrect .net 4.0 installation on server.
I googled and found out that sometimes during the .net 4.0 installation not all registry entries will be installes correctly :-( and this was exactly my problem.
In QVWS log I found the warning:
6/27/2012 14:36:59.6163967 Warning file not supported. (.ASPX)
After .net 4.0 re-installation everything works fine.