Inkscape OS X window dialogs off-screen on dual screen setup

[Andrew Saturn]

Mac OS X 10.10 Yosemite
X11 2.7.7
Inkscape 0.48
MacBook Pro 8,2 (15-inch, Early 2011)
2.3 GHz Intel Core i7
8 GB 1333 MHz DDR3
AMD Radeon HD 6750M 1024 MB
External monitor: Apple Cinema HD 23-inch (1920 x 1200)

Windows generated by the app (via opening a file, opening an open/save dialog, opening the path->trace dialog, etc) are all invisible/off-screen and can't be manipulated or dragged (only minimized to the dock via X11) on any dual monitor setup on my Macbook Pro.

Problem magically goes away when I close the laptop lid OR disconnect the external monitor. Comes back if I go back to a dual monitor setup.

If I open the app manually, the main window will appear and open/save dialogs work, but other dialogs still appear off-screen. Same as above - this problem is remedied by disabling one of the monitors (closing laptop or disconnecting the external display).

[su_v (suv-lp)]

Multi-monitor support of XQuartz on OS X >= 10.9 is known to be partially broken (not specific to Inkscape).

Linking as duplicate to
- Bug #1244397 “OS X Mavericks/XQuartz: limited support for multi-monitor setups”
  <https://bugs.launchpad.net/inkscape/+bug/1244397>