FPM to drop telnet connection with a string "shutdown"

Gents,

I am trying to drop telnet sessions including the word "shutdown" and i configured the following:

load protocol system:fpm/phdf/ip.phdf

load protocol system:fpm/phdf/tcp.phdf

class-map type stack match-all CMAP_STACK

 match field IP protocol eq 0x6 next TCP

class-map type access-control match-all CMAP_AC

 match field TCP dest-port eq 0x17

 match start TCP payload-start offset 0 size 1500 string "shutdown"

policy-map type access-control DRP_PMAP

 class CMAP_AC

   drop

policy-map type access-control SRV_PMAP

 class CMAP_STACK

  service-policy DRP_PMAP

int f0/1

service-policy type access-c in SRV_PMAP