sqlagent service startup timeout

Hello,

We're using SQL enterprise 2000 sp3 with windows server 2003 sp1 and sometimes when we reboot this server, sqlagent service cannot startup(30s timeout) but no any error state out(from sqlserver log, agent log, event viewer etc). But after several minutes later we can manually start this service. Any suspected cause of sympton? (e.g. application port conflicts).

Thanks and regards,

Wallace