Short information if you have something like a FAQ, known workarounds:
I am using Ubuntu 13.04 and was updating my devel environment to the latest revision.
For that I move my old directory "dev" to "dev_" and rename the extracted new revision to "dev".
This seems to have caused a cache problem or similar, as I received the following error on the login page if I try to login with my AD-LDAP-Account, even tried mutliple times (local admin was OK):
Fatal error: require_once(): Cannot redeclare class adldapcollection in /var/www/dev/functions/adLDAP/src/adLDAP.php on line 54
I did a grep and searched if anything has changed or if it is multiple times decalred / inlcuded but was not.
After a reboot the error was gone.