[TYPO3-english] feeditadvanced: "loading editing form" endless

[Stephan I.]

hi english list

since i got no answer in the german list, i try it here.

i have searched in all lists, but can't find a solution to my problem:

i have 2 typo3-installations with each a exact mirror on the same server.

- one installation and its mirror opens the FE edit window without 
problems, after having to re-login when clicking on the "edit" button. 
the system seems to be able to resolve the URL: http://mydomain.ch/#

- the other installation and its mirror hangs endless "loading editing 
form". when i click on the "close" button, i get a 404. it seems as if 
the system can't resolve the URL: http://mydomain.ch/#

versions (identical in all installations):
- typo3 4.3.3
- feeditadvanced 1.3.0
- templavoila 1.3.7

all caches are always cleared, again and again

TS-setup:
page.20 = USER
page.20.userFunc = tx_templavoila_pi1->main_page
page.20.disableExplosivePreview = 1
config.admPanel = 1

TSConfig:
admPanel default-werte for admin.

any hint or help?

thanks
stephan