Firefox 4 - Error initializing DeveloperCompanion Extension. Narwhal for XULRunner Extension not installed or enabled

[Jeff]

With the release of Firefox 4, I guess I made the mistake of
upgrading, now my DeveloperCompanion isn't working, with the same
error message as detailed in this thread:
http://groups.google.com/group/firephp-dev/browse_thread/thread/223f7afc9a561487

As suggested in that thread, I have tried uninstalling and
reinstalling the DeveloperCompanion and Narwhal extensions, as well as
installing them in a fresh Firefox profile, with the same error
message.

OS: Windows XP Pro SP3
Browser: Firefox 4.0
DeveloperCompanion version: 0.0.0master1101311421
Narwhal for XULRunner version: 0.0.0master1101311459

[Christoph Dorn]

If all goes well FF4 support for DeveloperCompanion will arrive mid April.

See:

http://groups.google.com/group/devcomp/browse_thread/thread/de93ee2aedb2e9cd

http://groups.google.com/group/devcomp/msg/3cf350b6dfc0f6a1

Thanks for your continued support.

Christoph