When calling any "Instance Action Chooser" (for searching edges, junctions, vehicles ...) fox-1.6 based sumo-gui (e.g. current svn sumo-r7813) crashes under linux with the following error message:
FXComposeContext: illegal window parameter.
This behavior can be reproduced. Other dialog boxes (e.g. the color wheel) work without crashes. Sumo-version based on fox-1.4 (e.g. sumo-r5409) are not affected by this error. Both fox versions were compiled with the same options enabled.