ORDS, SODA & JSON in the Database

I'm running APEX Listenerversion 1.1.3.243.11.40 on WebLogic 11g. The database is Oracle 11.2.0.3

I've got two managed instances in a cluster and the listener is deployed to the cluster. I've individually configured both APEX listeners (by going directly to each managed instance) to point to the same database.

I've configured the connection Pool to as follows on both managed instances:

<entry key="apex.jdbc.DriverType">thin</entry>
<entry key="apex.jdbc.InitialLimit">10</entry>
<entry key="apex.jdbc.MinLimit">10</entry>
<entry key="apex.jdbc.MaxLimit">20</entry>

When the server starts up I see the initial 10 connection no problems. After a while I see the following error message multiple times.

--- 5/15/12 11:44 PM ( 8 Hours 26 Minutes 44 Seconds Ago ) --- Unable to start the Universal Connection Pool: oracle.ucp.UniversalConnectionPoolException: Cannot get Connection from Datasource

netstat shows connections dropped below the min limit, sometimes to zero connections.

Has anybody seen this before? Also, is there a way to turn on detailed debugging or trace for the listener.I've turned on Show debug messages on console from listenerAdmin but that is really not detailed enough to see what is ultimately causing the Connection Pool problem.