System Information
Windows 7 64 bits - Nvidia GTX 780

Blender Version
Broken: 2.78a

Short description of error
When a grease pencil stroke is parented to a cube, and you move the cube, the rotation of the strokes is not coherent anymore.

Exact steps for others to reproduce the error
1/ Add a cube
2/ Draw with Grease pencil on the cube with surface option
3/ Parent the strokes to the cube
4/ Move the cube
5/ Go to Edit Strokes mode
6/ Select all the strokes
7/ Rotate the strokes

The rotation is not coherent anymore. The strokes rotate around something like a median point between the cursor and the origin of the mesh. Right now it rotates around some abstract transformation in space.

Thanks !