Comment #5 on issue 214 by allbery.b: mouse shift with java http://code.google.com/p/xmonad/issues/detail?id=214 It really isn't xmonad's fault. The JRE doesn't deal well with non-reparenting window managers. It has a small compiled-in list of non-reparenting window managers for which it will work around its own brokenness --- but any non-reparenting WM they didn't put into that list will have problems with graphics. The "official" solution is to use the SetWMName module in contrib to make xmonad advertise itself as a WM on that short list. MToolkit is a hack with its own bugs and no guarantee of continued support (the environment it was created for is these days quite dead).