I have such question/situation:

there is DB2 (8.1.5) server (called for example A) as data server
and there is DB2(8.1.5) server (B) with Information Integrator(8.1.5) as join server

Client connects to server B and work with database on A in fact.
database on server A contains data only, and some tables contains BLOB columns.

Client uses stored procedures that created on server B and there is such bug: stored procedure (that return resultset with BLOB) fails at second start, then succesfully run, and again fails and so on fails every second run

procedure contains only simple select from table with BLOB column

CREATE PROCEDURE MAILER.GetAttachmentByID ( Attachment_ID INTEGER )
SPECIFIC MAILER.GetAttachmentByID
DYNAMIC RESULT SETS 1
LANGUAGE SQL
P1: BEGIN
DECLARE result1 RESULT_SET_LOCATOR VARYING;

DECLARE cursorAttachments CURSOR WITH RETURN TO CALLER FOR
SELECT ATTACHMENTID, ATTACHMENTNAME,Replicated, ATTACHMENT FROM MAILER.ATTACHMENTS
WHERE ATTACHMENTID=Attachment_ID;

OPEN cursorAttachments;
END P1

error:
ERROR [560BD] [IBM][CLI Driver][DB2/NT] SQL1822N From data source "-423" unexpected error code "A". elements "func="block_fetch" msg=" SQL0423N ". SQLSTATE=560BD

but if Client execute simple select with BLOB columns - there is no error