Only one submit form generating You don't have permission to access /index.php on this server

Pulling my hairs out on this one.. Suddenly the form I'm w开发者_Go百科orking on generates Forbidden error..

You don't have permission to access /index.php on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Normally this is a rights issue, I know... But not in this case.. I restored an earlier backup of the form and this one works!

NOT WORKING: http://www.plastischechirurgie.nu/theme-options/index.html

WORKING http://www.plastischechirurgie.nu/theme-options001/index.html

I compared both forms but can't find a clue why one works and the other not!

Any help would be highly appreciated! Thanks in advance Quokka

Think it's mod_security not liking some or one field in the new form.. I'll post this question in mod_security section!