Storing zlib compressed data in a BLOB field

Hello,
I am trying to store a cPickled and then zlib compressed object in a  
BLOB field in my sqlite database.
This is the relevant line:
             cur.execute(query, (tuple_[1], sqlite3.Binary(tuple_[2])))
However, when I try to retrieve it back from the database, it appears  
to be of 'NoneType'.  Any idea what might be going wrong?  If I do  
not wrap it in sqlite3.Binary, it cuts off part of the data.  For  
example if what I put in is "'x\x9ck`\x8a-d\xd4\x03\x00\x06\x07\x01 
\x80'", what I get out is "'x\x9ck`\x8a-d\xd4\x03'"

Cheers,
Yi