Setting style sheet background-color property to QTabWidget causes its tabs to disappear when moving them.

Setting background-color property via style sheet in QTabWidget combined with movable tabs results in strange behavior of a QTabWidget - when color is set to i.e. blue or red, moving any tab causes disappearing of this very tab for the time of moving. When color is set to transparent, situation's similar, but only on first moving - subsequent ones are handled properly. This was tested on both Windows and Linux using WindowsVista and Motif styles.