XShape support doesn't work correctly with TightVNC

TightVNC uses XShape support 1.0 and the drag and drop can't be finished.
When drop fails we see the following messages in the console:

X Error: BadValue (integer parameter out of range for operation) 2
Extension: 128 (Uknown extension)
Minor opcode: 8 (Unknown request)
Resource id: 0x2

The same message were mentioned in this post:
http://qt-project.org/forums/viewthread/22310

Disabling the xshape support or using RealVNC which supports XShape 1.1 solves the problem.
If it can't be fixed, then the documentation should mention it, that Qt requires XShape 1.1.