Windows 7 desktop slideshow was not changing the background of a tab when the slideshow changed. I wrote some code to to handle a Windows 7 desktop slideshow transition if anyone is interested. Not sure how to submit updates to the project.
There are generally two ways:
1. Add a patch (see Tracker > Patches)
2. Fork the source code on github.com, commit the change, submit a pull request. Marko or I might request to rework the commit .