Windows 7 DWM weirdness

I'm looking to write a FOSS "Alt+Tab" replacement (window switcher) for Windows, since there are a few features I feel it's (still) lacking; but I'm noticing two quirks I can't seem to fix:

#1. (Somewhat Unrelated) In the default Windows 7 window switcher, one computer allows left clicking on a thumbnail to focus the window; however on another, similarly specced computer, I have to use a right click. The only difference between these two fresh installs is the theme. Any ideas?

#2. (Directly Related) In both the default Windows 7 window switcher and the DWM API output, minimized windows often have no thumbnail, and instead show only the taskbar. This has been a long running problem with the Windows API, and in the past I've seen the popular recommendation being "restore (un-minimize) the windo开发者_运维知识库w, take a screenshot, then re-minimize" - but this is sloppy and causes flickering, etc. Has anyone done this successfully using the newer DWM API?

If sharing code, I'd prefer C# syntax, but VB.NET will do as well. Thanks!