If I read my INI right, router first, then ntask. Are you running npas as well (premium anti-spam)?
Code:
ServerTasks=Replica,Router,Update,AMgr,Adminp,Sched,CalConn,RnRMgr,ntask,npas,HTTP,LDAP
And don't get me started on Symantec's "support" - I constantly get Domino crashes whenever npas loads new definition sets (roughly once a week) and they don't even recognize it as an issue.