Disabling SNAT on one virtual server, SNAT List is used :(

If I have SNAT in the SNAT List (aka default SNAT) it is apparently used on every virtual server. Is the source list the only way to change that behavior. I have one virtual server which takes incoming udp syslog data and sends it to a pool where only one server is active, enabling more graceful failover... Is there any simple way to disable SNAT on that one particular virtual server. Can have a negated entry in the source list?