Hmm, I took your statement about replying to pings too literally.

Would this help perhaps?
ip reflexive-list timeout 120

interface Ethernet0/1
ip address 172.16.1.2 255.255.255.0
ip access-group inboundfilters in
ip access-group outboundfilters out

ip access-list extended inboundfilters
permit icmp 172.16.1.0 0.0.0.255 10.1.1.0 0.0.0.255
evaluate tcptraffic

!--- This ties the reflexive ACL part of the outboundfilters ACL,
!--- called tcptraffic, to the inboundfilters ACL.
ip access-list extended outboundfilters
permit icmp 10.1.1.0 0.0.0.255 172.16.1.0 0.0.0.255
permit tcp 10.1.1.0 0.0.0.255 172.16.1.0 0.0.0.255 reflect tcptraffic

from
http://www.psionic.com/en/US/product...800a5b9a.shtml