i have problem whit apache on DA.
When i add new domain to DA after apache restared i get core dumped and apache doesnt start.
than i delete that domain and apache stars working...
That almost sounds like a filedescriptor limit is being hit.
This is the related guide for that: http://help.directadmin.com/item.php?id=9
Solution number 2 can be tried to lower the number of filedescriptors used (Comment out the ErrorLogs)
failing that, other things to try would be to remove mod_perl (libperl) from being Included in the main httpd.conf as sometimes it causes segfault.. Also doing a full apache recompile.