Cluster service oddities

I have an interesting issue with a cluster service Generic Application.

This problem just started to occur.

We go into cluster administrator and tell a particular application to stop. It shows that it's offline. However if you look in the task manager it is still running. If you start the cluster app again you now have 2 executables running. Repeat this process and I'll have 3, and so on. We have to terminate the process to get it to behave.

Any ideas what might be causing this issue?