When migrating my box to the newest version of php, I noticed that friendly URL's are no longer working when I enabled them.
Looking through several sites and forum, i've found out that a setting in php.ini can fix this. BUT it appears that it is a bug in PHP that is being used by UBB, which should be.
The quick fix is to edit the php.ini of your site, and set:
(disabling the original fix)
The comment in this settings tells it all:
; cgi.fix_pathinfo provides *real* PATH_INFO/PATH_TRANSLATED support for CGI. PHP's
; previous behaviour was to set PATH_TRANSLATED to SCRIPT_FILENAME, and to not grok
; what PATH_INFO is. For more information on PATH_INFO, see the cgi specs. Setting
; this to 1 will cause PHP CGI to fix it's paths to conform to the spec. A setting
; of zero causes PHP to behave as before. Default is zero. You should fix your scripts
; to use SCRIPT_FILENAME rather than PATH_TRANSLATED.
So UBB, please change your code the way it is supposed to be