Comment 29 for bug 585061

The autoupdate shouldn't be triggered for many hours. If you download a clean 3.6.13 released build from the website and run it, it shouldn't autoupdate very soon. You can then download the current 3.6.14pre build and try it there.

The other option is to use the profilemanager to set up a different profile for this but you shouldn't need to do so.