Depending on how the query which hits a stored procedure is formed, it
will either crash FB 1.5.3, the returned plan will contain gibberish, or
sometimes I'll just get back "PLAN ERROR!".
I have heard about problems with getting back invalid plan text. I
don't have a small test case, just our large database. I can remove the
confidential data and FTP it to an FB developer if needed.

Thanks, Rick DeBay