Leo, Josh, thanks for emailing me offlist.

I ended up fixing it by changing my Mac OS X JDK version to 64-bit 1.6 instead of the 32-bit 1.5.

On Mon, Jan 12, 2009 at 9:35 PM, Jacob Fenwick <jacob.fenwick@gmail.com> wrote:
On Mac OS X with the latest svn checkout of django, jython, and django-jython. When I try to run a view that access the database it says:

Caught an exception while rendering: driver [org.postgresql.Driver] not found
Original Traceback (most recent call last):
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/django/template/debug.py", line 71, in render_node
    result = node.render(context)
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/django/template/defaulttags.py", line 129, in render
    len_values = len(values)
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/django/db/models/query.py", line 160, in __len__
    self._result_cache = list(self.iterator())
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/django/db/models/query.py", line 275, in iterator
    for row in self.query.results_iter():
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/django/db/models/sql/query.py", line 203, in results_iter
    for rows in self.execute_sql(MULTI):
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/django/db/models/sql/query.py", line 1762, in execute_sql
    cursor = self.connection.cursor()
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/django/db/backends/__init__.py", line 56, in cursor
    cursor = self._cursor(settings)
  File "/Users/jacob/djython/jython-d/dist/Lib/site-packages/doj/backends/zxjdbc/postgresql/base.py", line 68, in _cursor
    self.connection = Database.connect(conn_string,
DatabaseError: driver [org.postgresql.Driver] not found

My postgresql jar file in on my classpath, as is indicated by the first time I ran runserver:

wuwei:foo jacob$ jython25 manage.py runserver
*sys-package-mgr*: processing new jar, '/Users/jacob/jdbcdrivers/postgresql-8.3-604.jdbc3.jar'

Oddly enough, I built a mysql backend, which tends to connect most of the time.