Limiting Traffic speed on a port

[hobbes80]

I have a 6509 with a Sup 2 module. I'm trying to limit the traffic on g1/1 to stay under 200mbps... I have a policer setup to do so, but last night our traffic exceeded 200mbps for a few moments and I want to know why it did... or if I'm missing a line.

mls qos
!
!
spanning-tree mode pvst
diagnostic cns publish cisco.cns.device.diag_results
diagnostic cns subscribe cisco.cns.device.diag_commands
!
class-map match-all ANY
  match access-group 1
!
!
policy-map POLICE-200Mbps
  class ANY
      police flow 200000000 100000 conform-action transmit exceed-action drop
!
!
interface GigabitEthernet1/1
 no ip address
 switchport
 switchport access vlan 200
 switchport mode access
 service-policy input POLICE-200Mbps
!
!
access-list 1 permit any
!
!
end