Is it possible that the server behind doesn't use the CARP LAN IP as gateway but a real IP of one of the systems?
Also is you WAN IP in a /24 subnet or something smaller? The IP sounds like a testsetup. The VIP and subnet has to be in the same subnet like the real IP of the Interface.
From what you wrote the pfSense config looks ok. Check your Client and server settings, maybe something is using a wrong gateway.
You also might want to rebuild that config with tha latest testing-snapshot: http://pfsense.com/~sullrich/1.0-BETA1-TESTING-SNAPSHOT-1-25-06/pfSense.img
It has several improvements and bugfixes. As you are running an embedded system that means you need to reflash the cf-media. I also would suggest creating the config afterwards by hand and not reimport the old one, just to make sure.