Automatic task execution on google app engine development server (python)

The docs for the python dev server say this about running tasks:

When your app is running in the development server, task queues are not processed automatically. Instead, task queues accrue tasks which you can examine and 开发者_StackOverflowexecute from the developer console...

But the release notes for version 1.3.4 of the python sdk (which I am using) say:

Auto task execution is now enabled in the dev_appserver. To turn this off use the flag --disable_task_running.

So maybe the docs are a little behind, right? Except when I go to "http://localhost:8080/_ah/admin/tasks?queue=default", I see this:

Tasks will not run automatically. Push the 'Run' button to execute each task.

Can tasks be run automatically or not? If so, what is the trick?

It seems the problem was that I was running the dev server with python 2.6 instead of 2.5. When using 2.5, everything worked.