PK/Dist-key hints to the Transaction is not working. I get the following error - NdbApiException Inconsistent key part length

I'm using the NDB Perl bindings.

PK/Dist-key hints to the Transaction is not working. I get the following error - NdbApiException Inconsistent key part length

Part of the Script:

my $myTransaction = $myNdb->startTransaction("mytablename",6528);

if (!$myTransaction) {
print $myNdb->getNdbError()->getMessage();
}

my $myOper = $myTransaction->getNdbOperation("mytablename");

$myOper->readTuple($NdbOperation::LockMode::LM_Read);

my $id_num = 6528;

$myOper->equalUlong("ATTR1",$id_num);

my $myRecAttr = $myOper->getValue("ATTR2");

$myTransaction->execute( $ndbapi::Commit );

my $foo = $myRecAttr->getInt32();

print "$foo\n";

$myTransaction->close();