As a CCIE, I would expect you to know the requirement of TCP/IP.
Consider the CSS as a nating device.
So, right now you have a client talking to a nated address, but the server response is going directly to the client un-nated. Therefore breaking TCP connectivity.
You have to guarantee that the server respone goes back to the CSS.
There different ways to achieve this.
1/- easiest solution is to make the CSS the default gateway of the server
OR
2/- configure client nat on the CSS. This is done with a "group".
ie:
group Client
vip x.x.x.x (same as your content rule)
add destination service
.... (add as many as needed)
active
OR
3/- Use policy routing to catch server traffic with source port equal to your application port (ie 80) and redirect the traffic to the CSS.
(1) is the easiest, (2) has a drawback - the server do not see the real client ip - so no stats possible, (3) is complex but a good solution.
Finally, if you have issues with a CSS, have a sniffer tool ready. Again, as a CCIE you should be able to troubleshoot connectivity issue with a sniffer.
Gilles.