GrowlMail didn't work after running the pgk installer

[cmyk]

From the instructions:

Installing GrowlMail is simple:

1) Quit Apple Mail.
2) Install the GrowlMail.pkg package.
3) Now relaunch Apple Mail. Whenever a new mail arrives, Growl will display a notification.
4) Go to Preferences/GrowlMail to configure GrowlMail.

That didn't work for me.
> Apple Mail Version 2.0.7 (746.2/750)
> OS X 10.4.6

I had to issue these 2 commands in the Terminal:
defaults write com.apple.mail EnableBundles 1
defaults write com.apple.mail BundleCompatibilityVersion 2

Cheers,
cmyk