Not sure if this was in ScreenOS 5 but try adding the keyword manual to the VIP configuration to make sure it is not doing probes before allowing the sessions.
set interface ethernet3 vip xx.xx.xx.xx 37777 "Security" 192.168.0.108 set interface ethernet3 vip xx.xx.xx.xx + 8554 "Security2" 192.168.0.108 set interface ethernet3 vip xx.xx.xx.xx + 81 "Security3" 192.168.0.108 becomes: set interface ethernet3 vip xx.xx.xx.xx 37777 "Security" 192.168.0.108 manual set interface ethernet3 vip xx.xx.xx.xx + 8554 "Security2" 192.168.0.108 manual set interface ethernet3 vip xx.xx.xx.xx + 81 "Security3" 192.168.0.108 manual
In the Web UI this is removing the check box on VIP for server auto detect.