Dear All, I am running Gmsh on my newly installed Mandriva LE 2005. The problem that I observe is the following: ** Whenever I CLICK on the GUI window and MOVE my cursor away, there will be a small (residual) SQUARE (black or white) remained on the display. Can anyone tell me what could be the problem? It is the problem from Gmsh or from the GUI Toolkit? Thanks! Hsuanyeh