Update Plugin - How to Enable Auto-Updating

Hello!

I have the latest Update Notifications (2.0.1) and the latest Wordpress Multisite (3.0.4) and no errors in my error log.

I added my API key to enable auto-update, the API box is green and gives a thumbs-up - and there are 4 plugins that need updating but they all have "DOWNLOAD PLUGIN" button instead of being able to auto-update. Are there some plugins that just don't auto-update? If so, is there a list of those? Or, did I not set it up properly - am I missing some step?

The plugins are:
Domain Mapping 3.0.1 -> 3.0.2
Easy Blogging 1.1 -> 1.1.2
Easy Blogging Wizard 1.0 -> 1.0.1
Rebranding WordPress Multisite 1.0.3 -> 1.0.5

Thank you for your support!
Kirsten