must appear in GROUP by clause issue

I have 2 (8.4.11) servers that I am testing the following query:

SELECT count(*),
maptrunc(cpeloc.lat, 4.5)::text || maptrunc(cpeloc.long,
4.5)::text AS name,
AVG(cpeloc.lat) AS lt,
AVG(cpeloc.long) AS lng
FROM cable_billing JOIN cpeloc USING(mac) LEFT JOIN davic USING(mac)
WHERE (status = 0 OR status is null) AND (cpeloc.lat is not null AND
cpeloc.lat !=0 AND cpeloc.long is not null AND cpeloc.long != 0)
GROUP BY name ORDER BY name;

On the first server the query works,

count | name | lt | lng
-------+-----------------+---------------------+----------------------
1 | 43.0425-94.2295 | 43.0429410000000000 | -94.2299740000000000
1 | 43.0525-94.260 | 43.0526200000000000 | -94.2603800000000000
1 | 43.054-94.224 | 43.0543150000000000 | -94.2244750000000000
(51 rows)

On the second server I get an error.

ERROR: column "cpeloc.lat" must appear in the GROUP BY clause or be used
in an aggregate function
LINE 1: select count(*), maptrunc(cpeloc.lat, 4.5)::text || maptrunc...

I was thinking the one server that works the maptrunc function was thought
of as an agg function, but they are both defined the same

\df maptrunc
List of functions
Schema | Name | Result data type | Argument data types | Type
--------+----------+------------------+---------------------+--------
public | maptrunc | numeric | numeric, numeric | normal
(1 row)

The only difference between the 2 servers are that the one that works
returns 51 rows and the one that does not I would expect to return 12000
rows.

I can make the one that does not work functional by changing

maptrunc(cpeloc.lat)::text --> max(maptrunc(cpeloc.lat))::text
maptrunc(cpeloc.long)::text --> max(maptrunc(cpeloc.long))::text

however, that one breaks on the first server with the error

ERROR: aggregates not allowed in GROUP BY clause
LINE 1: select count(*), max(maptrunc(cpeloc.lat, 4.5))::text || max...

Any suggestions would be appreciated.

George Woodring
--
iGLASS Networks
www.iglass.net