Too many open files

Hello! On MacOSX 10.4.10 which is an OD master, my log are filed with this: DirectoryService67: socket(PF_ROUTE) failed: Too many open files (60000 times in one week...) It happens at exactly every hours 44 minutes 18 seconds 161 times. At the same time, it makes a lot dns request for "_kerberos-master._udp.XXXXXXXXX.COM IN SRV +" The server works fine, but there's probably a cronjob that go crazy and i would like to know why it's happening. Thanks a lot! Fred