Doesn't work in FF8+, window.navigator.service is undefined

[forresto]

The extension seems to be enabled, but http://mozilla.github.com/rainbow/example.html says "The Rainbow add-on could not be loaded!" Also when served from localhost. In the console:

[10:44:55.520] window.navigator.service is undefined @ http://localhost:8888/example.html:5

The extension isn't compatible with Beta or Aurora.

In about:config (I set this up as a custom field, as it wasn't there after installing the extension):

extensions.rainbow.allowedDomains;["localhost","mozilla.github.com"]