first of all, thank you for developing this option for Firefox and Chrome. It's been great so far, stable and light.
But of course there has to be some nagging as well - the latest version has an issue with rearranging tabs, at least in two pc's I've installed it to. When you grab from a tab and begin to move it, it instantly jumps into a new window and minimizes rightaway. It displays in the windows taskbar as a separate window, but the actual window can only be seen by right-clicking the taskbar item and maximizing the window.
It's not a huge problem, but causes minor irritation anyway.