can’t it be a win 8 related? Rawa you got win 8 too? (if yes it might be some compatibility issues with wxWidgets vs win 8 or something keymaster could fix)
This issue first came to me in version RC9, but I have sinned by not new video card drivers. Later, after the Alfa5 on 3Dcentre.ru many have encountered this. From my observation: it is more common when using higher resolutions 1500 (never had at 800/600), more frequently in the book page unauthorized persons (eg 1300/2000)