AS400-DB2-JAVA SQLException error -7008

When I execute an 'update' SQL statement with setAutoCommit(true) it works.
When I do same with setAutoCommit(false) I get an SQLException... WHY????

try
{
   System.out.println("Retrieving: "+keyInCC+" "+keyInYY+" "+keyInMM+" "
+keyInDD+" "+keySequence);
   // Create statement and Read record
   psPerKeyInput Ðclipper.prepareStatement("SELECT * FROM JAVA.UPBOKINTST
WHERE BRDICCß AND BRDIJJß AND BRDIMM Ð? AND BRDIDD Ð? AND BRRENR Ð?");
   psPerKeyInput.setShort(1,(keyInCC));
   psPerKeyInput.setShort(2,(keyInYY));
   psPerKeyInput.setShort(3,(keyInMM));
   psPerKeyInput.setShort(4,(keyInDD));
   psPerKeyInput.setInt(5,(keySequence));
   rs ÐpsPerKeyInput.executeQuery();
   System.out.println("Record Retrieved: "+keyInCC+" "+keyInYY+" "
+keyInMM+" "+keyInDD+" "+keySequence+" successfully");

  // Update record to see if it's free
  clipper.setAutoCommit(false);
  System.out.println("Updating        : "+keyInCC+" "+keyInYY+" "+keyInMM+"
"+keyInDD+" "+keySequence);
  psUpdateRecord Ðclipper.prepareStatement("UPDATE JAVA.UPBOKINTST SET
BRSTATß WHERE BRDICCß AND BRDIJJß AND
  BRDIMM Ð? AND BRDIDD Ð? AND BRRENR Ð?");
  psUpdateRecord.setString(1,("TR"));
  psUpdateRecord.setShort(2,(keyInCC));
  psUpdateRecord.setShort(3,(keyInYY));
  psUpdateRecord.setShort(4,(keyInMM));
  psUpdateRecord.setShort(5,(keyInDD));
  psUpdateRecord.setInt(6,(keySequence));
  psUpdateRecord.executeUpdate();
  System.out.println("Record Updated   : "+keyInCC+" "+keyInYY+" "
+keyInMM+" "+keyInDD+" "+keySequence+" successfully");
 }
 catch (SQLException e)
 {
  aFreightQuotation Ðnull;
  System.out.println("problem with record retrieval because error: " +
e.getErrorCode());
 }