| | Problem Solved
then main problem is name of content-type.
don't know why, the blackberry system don't allow
me to use my own name likes "application/x-myapps".
the blackberry will detect as application/octet-stream.
i register attachment handler, and print out every
message that have attachment via EventLogger.
now, my application run well,
attachment handler register at application open,
and attachment handler remove at application close.