Size limit on xmlType CLOB?

Question

I seem to be running into a limit on the size of the CLOB returned from a select into an XMLType. When it gets around 275K it doesn't return a value anymore - it does not return an error, just the .getclobval is empty. I am using the Select XMLAgg(XMLElement) Into XMLType method. Using 9.2 ORA DB running on UNIX. If anybody knows if there is actually a limit, it would be greatly appreciated. I know I can use the dbms_xmlgen method but I want to avoid that if possible.
The full stored proc text:
PROCEDURE GetISRNumber ( RetXML OUT CLOB ) IS
xmlTypeRet xmlType;
begin
SELECT xmlagg(XMLELEMENT("Record", XMLELEMENT("JobNumber", ISR.ISR_NO)
, XMLELEMENT( "address", isr.COMPL_ADDRESS)
, XMLElement( "Street", isr.Street_Name1)
, XMLElement( "CivicExtensionDFJOIK", isr.ALPHA_CIVIC)
, XMLElement( "Created_Date", isr.created_date)
)) AS "XMLReturned"
INTO xmlTypeRet
(Select ISR_NO, COMPL_ADDRESS, Street_Name1, ALPHA_CIVIC, Created_Date FROM ISR)
RetXML := xmltyperet.getclobval();
RetXML := '<Job>' || RetXML || '</Job>';
EXCEPTION
WHEN OTHERS THEN
Case SQLCODE
When -30625 Then
RetXML := '<Job>No Records Found</Job>';
Else
Raise;
END CASE;
end GetISRNumber;

Answer 1

This link will be usefull
for this problem
http://www.oracle.com/technology/sample_code/tech/java/codesnippet/xmldb/HowToLoadLargeXML.html