Problem with incoming load balancing

[xxprowler]

hi,

i'm using pfsense 1.2.3-RC3, and trying to setup a load balanced mysql cluster.
i can access to each node directly but can't through the VIP.
i see the two nodes as online but marked as yellow, what does it mean ?

update:
i forgot to mention that the load balancing is made on the same subnet, meaning that the hosts that send requests and the hosts behind the vip(and the vip itself) are on the same subnet.
it looks like i need to do source NAT, i see 3 types of NAT, which of them should i use to do that ?

thanks.