You will have better and faster results if you use check_snmp instead of check_ifoperstatus. It is much faster, and just may solve your problem. Just a tip: I'm running over 1000 service checks every 5 mintues. 80% or more are queries to ports on a switch or host to see the ethernet ports status. This would not be possible with check_ifoperstatus, becuase it's just to slow.
$USER1$/check_snmp -H $HOSTADDRESS$ -C $ARG1$ -o $ARG2$ -r $ARG3$ -l $ARG4$ -m $ARG5$