PostgreSQL support / filter never engages

Hi,

I've installed Interwiki on my Drupal 4.6.2 site, backended with PostgreSQL. I used the attached PostgreSQL database, very straight-forward. In spite of the creation of a new input format using Interwiki, it never seems to engage.

I've peered into the database to ensure that it's going through the module (it is) and I've even tried to trace the execution of the PHP code by adding echo statements, but I have a lot of trouble following the code. I think the problem lies within this test on line 213:

if (! ($matcha[$match[1][$index]] == "")) {

Nothing in here ever seems to trigger. I did remember to load the database, too. :)

Please let me know if there is anything else I can give you to assist in discovering the problem here.