Sp_send_dbmail Erroring Out On Line 476?!

Hello all -

I'm using SQL Server 2005. I'm trying to send an email with query results attached.
I've enabled database mail (surface config, config wizard, profile set, accounts loaded).
I know database mail itself works as I'm able to send plain text messages as well as messages with HTML embedded.
However, when I try to format a query to send attachments with mail, as shown in BOL; I always get this error message -
<snip>

Msg 14661, Level 16, State 1, Procedure sp_send_dbmail, Line 476

Query execution failed: Error initializing COM

Msg 0, Level 11, State 0, Line 0

A severe error occurred on the current command. The results, if any, should be discarded.
<snip>

Here is a sample of the query...

DECLARE @WHO VARCHAR(255)

SET @WHO = '<name would go here>'

EXEC msdb.dbo.sp_send_dbmail

@profile_name = 'sqlmail'

,@recipients = 'my.name@wouldgohere.com'

,@subject = 'testing attachment'

,@query = N'SELECT email_body

FROM WFS_non_stock_email_sendit_history

WHERE who_entered = @WHO

ORDER BY date_created DESC

OPTION(MAXDOP 1)'

,@execute_query_database = 'whaley'

,@attach_query_result_as_file = 1

,@query_attachment_filename = 'TESTATTACH.txt'

,@query_result_separator = ';'

If I were to run this query outside of this dbmail code, the query works fine.

If I can believe the go to line editor, line 476 in the sp_send_dbmail sproc is...

DELETE sysmail_attachments_transfer WHERE uid = @temp_table_uid


My problem here is this is a system sproc that MSFT built. I don't understand why I would get this error message instead of something more definitive and indicative of the problem.

Has anyone else seen this problem? I really need to be able to send attachments.

Thanks

Randyvol