query parsing bug?

known behavior or bug?

fr=# select count(*) from foo where foo_id!=-1;
ERROR: Unable to identify an operator '!=-' for types 'int4' and
'int4'
You will have to retype this query using an explicit cast

fr=# select count(*) from foo where foo_id!= -1;
...
(1 row)

Notice the space (or lack thereof) between != and -1. It only seems to
happen with != and a negative number.

fr=# select count(*) from foo where foo_id=-1;
...
(1 row)

fr=# select count(*) from foo where foo_id!=1;
...
(1 row)

This is with 7.1.3, via psql. I haven't tried the query via another
interface (ie, JDBC).

eric

ps, wonder if I should be using <> instead of !=