Hi Uwe,
Well, before I directly answer your question, I will explain what I've found out so far:
The issue is a security "feature" of modern web browsers that don't perform javascript authentication (or something to that effect) that is ran on a remote machine. So, if I have the application on machine A, and I try to access it from machine B, it won't work correctly. A workaround for this is to run google chrome with the flag --disable-web-security; however, that does not help us for testing it on the iPad.
How are you testing your apps?
Greetings,
Vanessa