Clustering 7.1.1 across data centers not working

Has anyone been sucessful in getting the Oracle (Tangosol) Coherence product to work across different data centers (subnets)? This is the product used in WM 7.* to manage clustering.

we use it like that.
We do not have any issues. Do you have multicasting enabled on your network?
We had issues when our multicasting was disabled. Once we enabled it, it worked like a charm.

It was our F5 load balancer that was causing the problem. We will be moving our servers around to work around this within the next week or two. Everyone I talked to though has said doing mulicast across physical data centers is not a good idea.