SPI example does not work for 7.1beta4

Folks,

I am learning and using SPI. In PostgreSQL documentation chapter "Server
Programming Interface," there is a small example name "execq(text,
int)".

This example works as the document says on 7.0.3 and earlier version,
but this example DOES NOT work on my 7.1 beta4.

This is the error message I got.  I wonder does anyone test your SPI
functions on 7.1 beta?  Does anyone notice the problem I got here?
I know I should test this under beta6 before I post this message, but my
co-worker's anti-virus s/w gave him a virus warning message after him
finished the download of 7.1beta6 .gz!  :-)

------------
db1=# select execq('create table a (x int4)', 0);
pqReadData() -- backend closed the channel unexpectedly.
        This probably means the backend terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!#
------------

Thanks for your help

--
LM Liu