delays when routing to Internet

[gmarshall7000]

We have a Main switch which connects reasonably well to the internet and to our ISA server. Using trace Route from other switches on our network, we experience delays of several seconds whilst the Trace Route command "waits for the local IP address" 

This delay only happens when tracing the route to our ISA server(172.16.9.3). If we use trace Route to our servers(172.16.9.1, 172.16.9.4) or the main switch, the response is almost immediate (although the local ip address is consulted first, this happens in milliseconds.

If we had a route in our routing table on these local switches that pointed to our ISA server(172.16.9.3), I imagine that would remove the delay we are experiencing, but I am having trouble modifying the existing ip routes on these 5500 switches