Hi Philip,
It might be the configuration on the Cisco 7200 Router, you might have to see if all the access-lists allow IPSec traffic (symptom for traffic not passing after tunnel gets established). Some Route that exists on the 7200 which causes the traffic to be sent out somewhere else. You might have to share the configs with a Cisco Engineer to get a resolution on this, as the 7200 seems like a passthrough router in this case and shouldn't cause any problems if configured properly.
Regards,
Aamir