I also have an issue with Fences 2.1 running with Windows 8.1 Preview. I've been running Fences 2.1 on Windows 7 and 8 just fine. After upgrading my laptop with the W8.1 preview update, my fences show up as normal, but I can no longer drag icons on the desktop, or drop new icons on the desktop. When attempting to do a drag or drop, the mouse cursor shows up as disabled (the little circle with a slash through it). To verify that this was a Fences issue, I uninstalled Fences, rebooted, and could once again drag and drop icons. I then reinstalled Fences and the problem immediately recurred.