operator is not unique: integer || integer

yeah, its clear that an upgrade from 8.1 to 8.3 is impossible for us
without a major relase.
there are to many changes so the whole project has to be rechecked.

another example:

in 83:

postgres=# SELECT 1::INTEGER||1::INTEGER;
ERROR: operator does not exist: integer || integer at character 18
HINT: No operator matches the given name and argument type(s). You
might need to add explicit type casts.

83 with autocast from peter e:

ERROR: operator is not unique: integer || integer

in 81:

postgres=# SELECT 1::INTEGER||1::INTEGER;
?column?
----------
11
(1 row)