nsIJSON.encode -> JSON.stringify, nsIJSON.decode -> JSON.parse Rated 5 out of 5 stars
TGM is very-very-very usefull addon, greatly facilitates the work with a lot of tabs sets.
But unfortunately, recently the author can not actively develop it, and appeared problems with newer versions of FireFox (especially with test builds of versions 7 and 8).
One of them: with last 2-3 nightly builds of FF 7.0.a2 Aurora this addon was broken.
This happened because in the past builds of the FireFox functions nsIJSON.encode and nsIJSON.decode were removed.
To resolve this issue we need to replace nsIJSON.encode and nsIJSON.decode in the files "resource/modules/TabsGroupManager.jsm", "chrome/tabgroupsmanager.jar/content/TabGroupsManager.js", "chrome/tabgroupsmanager.jar/content/options.js" with JSON.stringify and JSON.parse, respectively (https://bugzilla.mozilla.org/show_bug.cgi?id=645922#c5).
Sorry for my English :)