Difficult Performance Problem

I have a system of BPELs and EJBs that perform a task.  Most of the task is driven by an EJB, which invokes a few BPEL processes.  One of the BPELs takes about 2 seconds to run.

The problem is that if for any reason the client (I'm using SoapUI and Netbeans unit tests) goes away, such as a timeout, then the next time the process is run, the same process that took 2 seconds to run takes more like seven seconds.

Let the client time out again, and that becomes more like 2-3 minutes.  Do this 3-5 times and the system becomes unusable, the delay becomes several hours.

I have used logging to isolate the time being consumed to be just between the Java/EJB's call to the BPEL's web service, and the start of the initial receive action in the BPEL.

How can I avoid this problem?
Thanks