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?

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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.