Messages Not Routing Properly

[fatdog302]

I have 6 Exchange servers, one a bridgehead(site1). I have recently installed a Exchange 2003 server (site3) and it will not route directly to site 1. There is a connector joining the two site but it will insits on using another connector to deliver the messages, so instead of routing from site3 directly to site1 it will go by one of the other sites. I started removing all the other connectors one by one until i was eventually left with only site1 connector and it would send the messages through at all. I did a trace on the message and this is was came up:

Event:
SMTP: Store Driver: Message Submitted from Store
SMTP Message Submitted to Advanced Queueing
SMTP: Started Message Submuission to Advanced Queue
SMTP: Message Submitted to categorizer
SMTP: Message Categorized and Queued for Routing
SMTP: Message Routed and Queued for Remote Delivery

Then i added one of the connectors for the other sites back in and it worked. Does anyone have any ideas????

Thanks
Costa.