Some people have experienced confusion registering the extension with the web service.
either watch this little
instructional (http://www.mystickies.com/instructions/example.html) that will soon be packaged with the extension or read this:
First you need an account at www.mystickies.com (free)
logging into MyStickies in most cases registers the extension with the service. If it does your user name should appear on the far left of the toolbar. If instead it says Accounts, click Accounts -> Manage Accounts -> Add Account and add your user name and password to the toolbar. This should make your notes persistent.