Review for Gmail Manager by slumbergod
Rated 5 out of 5 stars
As someone else suggested, try going to the home page for the developer and manually upgrade to 0.6.1
This fixed the problem for me so chances are it will help a lot of others too.
(right click on status bar gmail manager icon and select Go To Homepage)
To create your own collections, you must have a Mozilla Add-ons account.