You know, it feels like 90% of the development and support on this application goes authentication. The OAuth just doesn't want to work for me, does it?
It looks like uninstalling and reinstalling the extension fixes most, if not all, of these issues. I've released version 220.127.116.11 of the extension, which will detect if you're having auth issues and will attempt to reauthenticate you. Meaning it will open a new browser window, and will ask you to log in and grant access again.
I'm sorry for all these issues. Really, I want to make them stop as much as you all want to see them stop. I appreciate everyone who is filing bug reports and is helping to track down the issue. You all are amazing.
In related news, I've decided to create a group of trusted Beta Testers for the application. If you're interested in testing the new features of the application before they roll out to all 2000+ people, and are ok with buggy releases (you must be, if you're still using the application... sorry!) please send an email to paddy at android 2 cloud dot org. I'll invite you to the beta tester Google Group, and you'll get instructions from there.
Thanks everyone for your support. You all rock.