what to do when Rails generated select statements don't work on custom types

Running FC6 with RoR 1.1.6
I'm using a custom type called 'uuid' based on code from this project.
http://gborg.postgresql.org/project/pguuid/projdisplay.php

Here's a description of the ksessions table.

Table "public.ksessions"
   Column | Type |
Modifiers