[c-nsp] Class-based policing problem

[Justin Shore]

I'm trying to configure class-based policing on a 2821 running 
12.4(11)T1.  I have a interface on a NM-16ESW configured for an access 
VLAN.  The SVI for that VLAN is what I'm trying to apply the policy to. 
  Here's what I'm working with:

class-map match-all customer-class
  match access-group 12
!
policy-map customer-policing
  class customer-class
    police 5000000 937500 1875000 conform-action transmit exceed-action 
drop
!

ACL 12 is a standard ACL with the subnet of the customer in question. 
When I try to configure the service-policy on the SVI I get this error:

2821-1.clr(config-if)#service-policy input customer-policing
Configuration failed!

Is class-based policing supported on these interfaces and on this 
hardware?  I've always used CAR for these applications but it was not 
giving the results I was hoping for.  That's what I'm trying policing 
instead.  Have I configured class-based policing correctly?  My goal is 
to rate-limit traffic to 5Mbps symmetric.

I'm working from the examples on this page:

http://tinyurl.com/2c9r6d

Thanks
  Justin