no frontpage access to change userdetails in community build

Hi,

I had a stable installation with

Joomla 1.5.10 (.htaccess and SEO)
CB 1.2
FCK Editor 2.6.3.9.b
IE 7.0

until yesterday. I tried some changes in FCK Editor 2.6.3.9.b (Frontend Toolbar mode) and in the CB Configuration (Pictures/Allow Upload)

Now ist is impossible for users to edit their profile in frontend. Follwing "Windows Internet Explorer" message appears:

"Windows Internet Explorer"
Die Internetseite "www.domain.de/profil-aendern" kann nicht geöffnet werden.
Vorgang abgebrochen

in english:
"Windows Internet Explorer"
The Website "www.domain.de/profil-aendern" cannot be opened. Action cancelled.

See the failure message without SEO in attacheed file.


Any ideas?