SQLDataSource warning

[claudiobosticco]

v8.2p_2012-06-25/PowerEdition Deployment

sometimes I got this warning in tomcat logs:

2012-07-27 17:21:35,141 WARN SQLDataSource Exception while ending transaction connection
java.lang.Exception: No current connection for 'null'
at com.isomorphic.sql.SQLTransaction.endTransaction(SQLTransaction.java:217)
at com.isomorphic.sql.SQLTransaction.endTransaction(SQLTransaction.java:212)
at com.isomorphic.sql.SQLDataSource.freeResources(SQLDataSource.java:2503)
at com.isomorphic.datasource.DSRequest.freeResources(DSRequest.java:3449)
at com.isomorphic.datasource.DSRequest.finalize(DSRequest.java:2445)
at jrockit.memory.Finalizer.doFinalize(Finalizer.java:29)
at jrockit.memory.Finalizer.access$300(Finalizer.java:12)
at jrockit.memory.Finalizer$4.run(Finalizer.java:186)
at java.lang.Thread.run(Thread.java:662)

what does it mean?