When atttempting to add a custom brush watermark to a photo that has been expoted from Lightroom, a single mouse click produces approx. 20-30 brush strokes, always to the upper left. The termination point of the duplicate brush strokes seems to be the origination point, not where the brush postion is indicated. Additionally, when trying to "undo", the mouse cursor has to be moved to the right within the highlighted "undo" line in order for it to be selected. This issue is not present when the impoted image is closed. Brush function and mouse cursor position is normal when creating a new document.