Passing arguments to executemany

Hi,
I switched from MySQLdb to oursql and I very happy with it. I just tried using executemany for this query

query="""
select unix_timestamp(rev_timestamp)/86400.0, page_namespace
from revision r join page p
on r.rev_page = p.page_id
where rev_user = ?
order by rev_timestamp
"""

In my script I call it in the following fashion:

executemany(query, [(10,), (20,)])

But I get the following error:

 ---------------------------------------------------------------------------
ProgrammingError Traceback (most recent call last)
/home/giovanni/repos/lifecycle.git/<ipython-input-9-0f01344bcf0c> in <module>()
----> 1 cursor.executemany(query, [(20,), (10,)])

/usr/local/lib/python2.7/dist-packages/oursql.so in oursql.Cursor.executemany (oursqlx/oursql.c:16181)()

/usr/local/lib/python2.7/dist-packages/oursql.so in oursql._Statement.execute (oursqlx/oursql.c:8976)()

ProgrammingError: (None, 'executing this query would cause rows to become unfetchable', None)

*************

what does it mean? I am using oursql 0.9.2 on Python 2.7 Ubuntu 11.04.

Cheers

G