Ok, so XML suxors and all, but if you're going to use XML then *use XML*. When you rev the god damn devstudio you don't break the old file format, you just add new tags for whatever new crap you feel you need to add. You don't put the devstudio version in the header of the file, you put on the individual tags that are specific to that version.
If you need to do per-version settings files, put them in a different file than my basic list of what my source code is and how to build it. And of course don't mix up your GUI cache with my project data.
The thing that really boggles my mind is how they can make such a huge mistake, and then stick with it year after year. It's sort of understandable to make a mistake once (though I think this one was entirely avoidable), but then you go "whoah what a fuckup, let's change that". Nope.
(of course they've done the same thing with their flagship (Office). It's crazy broken that I can't at least load the text and basic formatting from any type of document into any version)