@Deimos Any news on this? George is totally right about updating to a current version is the only way we can help you if it turns out to be a bug in the version you use.
Beside that you might want to look into cleaning up the database to see if it makes a difference: https://wiki.fogproject.org/wiki/index.php/Troubleshoot_MySQL#Database_Maintenance_Commands
Has this ever worked? When did it work last? What changed since then?
This is a very interesting site. I can not handle the problem at the moment, because I have to work very actively with it at the moment and the system must not break down. I have to copy/paste the correct AD-Files into the field and save them (group data). THis works for every single group or host. But not generally. Anyway, I’ll just update after this month and see what happens.