NIS version: 20.6.0.27. Norton Toolbar version: 2013.4.15.4 According to this announcement, these are correct and should support Firefox 37.
Under "about:addons", the toolbar is present and appears to be active. However, Norton Toolbar is not present in the FF menu any longer and ID Safe is not working. I tried deleting my profile and creating a new profile without any other addons to see if another addon was causing this, but no change in the above behavior.
When I revert to FF 36.0.4 all it works properly.
Sorry if this is a double post - I posted earlier but there doesn't seem to be a record of it even under my profile's recent activity.