I installed v9SP1B2, created a brand new PostgreSQL DB using the script on your web site, created a new system ODBC data source for that new database, and tried to connect to it. After a few seconds, I get 5015-8038: "Database Error: The selected database is not a ThumbsPlus database. If you are connecting to a client/server ThumbsPlus database, check with the database administrator to ensure your login has appropriate privileges."
I turned on logging in the ODBC control panel and found this:
query='Select * from ThumbsPlusDatabase'
[13.561]ERROR from backend during send_query: 'SERROR'
[13.562]ERROR from backend during send_query: 'C42P01'
[13.562]ERROR from backend during send_query: 'Mrelation "thumbsplusdatabase" does not exist'
I'm guessing that you need to quote the table name to keep it from getting folded to lowercase. I can duplicate that same problem in the psql shell.
Thumbs9=# select * from ThumbsPlusDatabase;
ERROR: relation "thumbsplusdatabase" does not exist
LINE 1: select * from ThumbsPlusDatabase;
^
Thumbs9=# select * from "ThumbsPlusDatabase";
attribute | value
--------------------+-------
thumbnail_width | 320
thumbnail_height | 320
thumbnail_type | 6
thumbnail_compress | 88
thumbnail_files | 0
volume_match | 3
like_style | 1
transactions | 0
background_conn | 1
quote_style | 2
(10 rows)