[Serusers] HELP: Reentrant Main Route Block

Hi All. We've got a complex network configuration whereby we're using Linux firewall wall load balancers which sit behind a Cisco 3600 router and behind the firewall/load balancers (there are more than one) we have multiple SER proxies. We're using a virtual IP (VIP) on the public side of the load balancers. Anyhow, when a message is sent to a SIP proxy it is hitting the main route block in ser.cfg But then it somehow hits the main route block again before being t_relay()ed. So it appears that the main route block is reentrant. I didn't think this was possbile. I added a P-Hint: header and the first pass through the main route block the statement (uri==myself) is TRUE, then the second pass through the main route block (uri==myself) is FALSE. Can any give a pointer? Regards, Paul