User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:16.0) Gecko/16.0 Firefox/16.0 ID:20120625030537 ShiftIt (https://github.com/fikovnik/ShiftIt) is an application for OS X that changes the position and size of windows when triggered by keyboard shortcuts. It works for all windows except unresizable ones. Until recently, it worked with Firefox too. Starting with (I believe) the Nightly build from 2012-06-20, any attempt at moving/resizing Firefox using this application fails. Instead of moving/resizing, the Firefox window remains in place, and X11.app opens. The following error is added to the system log: ShiftIt: ShiftIt action: [ACTION] failed: AXError: Unable to get active application, X11Error: No X11 active window found This is happening on Mac OS 10.7. I could *not* reproduce this using Nightly and and ShiftIt on Mac OS 10.6. I'm not really sure how to debug this, but I'm happy to provide additional information.
This problem is resolved when using a development version of ShiftIt. Possibly related: https://github.com/fikovnik/ShiftIt/issues/87 Unlike that issue, however, my failures were specific to Firefox (everything else worked) and began after an upgrade to Firefox. Still, marking this as resolved.