1.2.2-RC2-K for Linux:DragDrop: Drop can not work properly

Redhat Linux 6.1J, build 1.2.2-RC2-K

Drop can not work well.

In case of 3 button emulate,
Drop needs a mouse clicking with two(right&left buttons) of a mouse.
Then, Drop can work.

In case of not 3 button emulate,
DragDrop causes a application freeze.

To reproduce,
1. Compile and run a attached program.
2. Drag and drop from drag area to drop area.
3. Then, application is hung.