Frontend - Backend protocol change?

I am testing the Smalltalk PostgreSQL drivers against PostgreSQL 7.2 and
I am seeing a change in the messages I get back from the backend for one
of my tests, even though the protocol version number is "0 2 0 0" in
both cases.

To run this test, I switch on message logging and connect to a 7.1
database (Redhat RPM version 7.1.3-2) and all is well. The log for this
test is attached as trace-7.1.3-2.txt.

When I run the same test, from the same Smalltalk image, when connecting
to a 7.2 database (Redhat RPM version 7.2.1-5) the sequence of messages
is different, and my driver code flags an exception. The log for this
test is attached as trace-7.2.1-5.txt.

The difference is that at 7.1 there is a CompletedResponseMessage
terminating each CursorResponseMessage. At 7.2 there is only one
CompletedResponseMessage which terminates the second
CursorResponseMessage (so I got two CursorResponseMessage's, one
immediately after the other).

Here is the snippet from each log showing the query ('update
exdiTest21data set name = ''Harry'' where name = ''Larry'';') and the
responses from the back end.

My question is: which is "right" the 7.1 behavior, or the 7.2 behavior?

*************************************
From the 7.1 log:

June 28, 2002 5:30:48.718
>>>>> QueryMessage
'update exdiTest21data set name = ''Harry'' where name = ''Larry'';'

June 28, 2002 5:30:48.733
<<<<< CursorResponseMessage
Cursor name: blank

June 28, 2002 5:30:48.736
<<<<< CompletedResponseMessage
Command tag: INSERT 273804 1

June 28, 2002 5:30:48.740
<<<<< CursorResponseMessage
Cursor name: blank

June 28, 2002 5:30:48.744
<<<<< CompletedResponseMessage
Command tag: UPDATE 1

June 28, 2002 5:30:48.749
<<<<< ReadyForQueryMessage

*************************************
From the 7.2 log:

June 28, 2002 5:06:31.176
>>>>> QueryMessage
'update exdiTest21data set name = ''Harry'' where name = ''Larry'';'

June 28, 2002 5:06:31.304
<<<<< CursorResponseMessage
Cursor name: blank

June 28, 2002 5:06:31.307
<<<<< CursorResponseMessage
Cursor name: blank

June 28, 2002 5:06:31.311
<<<<< CompletedResponseMessage
Command tag: UPDATE 1

[at this point my driver flags an error]