Can't use Database.load(...) when all the columns in the table are part of the primary key

I'm getting this error when use the Database.load(...) when my table has only columns wich are part of the primary key:

java.lang.IllegalStateException: Transaction org.castor.persist.LocalTransactionContext@147c1db does not hold the read lock
...
java.lang.ArrayIndexOutOfBoundsException: 0
at org.exolab.castor.jdo.engine.SQLStatementLoad.executeStatement(SQLStatementLoad.java:332)
at org.exolab.castor.jdo.engine.SQLEngine.load(SQLEngine.java:349)
...

The table the unitTest:

create table FSIM17(
NUMCIA decimal(3,0) NOT NULL,
NUMALM decimal(3,0) NOT NULL,
IPWAS CHAR(15) NOT NULL,
primary key (NUMCIA,NUMALM,IPWAS)
)