If you install the .NET 2.0 framework from community support first, then Paint.NET v2.72 does install, but crashes on start up with a message abut an unhandled error.
I downloaded 2.72 from http://www.filehippo.com/download_paint.net/1510/ if anyone else wants a try.
Considerations: I'm using Mac OS X 10.6.2, CX 9.0.0, new WinXP bottle with .NET 2.0 installed (the .NET 2.0 SP1 failed to install)