1.05 works with 2.3.1 and the 2.2.x series of WordPress.
1.01 worked only on 2.3.1
In WordPress 2.2.x, the subpages widget is currently not available. There’s also no auto meta keywords due to the tag system missing in 2.2.x (it was introduced with WordPress 2.3.1).
A version compatible with WordPress 2.1.x is coming out soon.