Anyone familiar with the following error : Exhausted Resultset

I have a Java PX that uses IQUERY to retrieve a list of documents and process them with some logic. Occasionally, upon exiting the PX, some of the documents receives a "Exhausted Resultset" error when I tried to view the document from the web client. Has anyone ever experience such an error?

I also ran into the same error when the following statement fails trying to add an item to the Affected Items tab:

IRow affectedItemRow = affectedtable.createRow(docObject);

It appears to be some sort of locking problem in Agile. After a period of time, the error goes away.