I am having the same issue as the original poster. After approximately 15 minutes of using X13, I encounter a problem whereby, for example, if I insert a door into a wall, the crosshairs continue to remain as the door insertion icon and will not allow me to complete any other tasks, e.g. inserting a window into the wall. Instead, if I click anywhere else on the screen, or move the mouse around on the screen, the door just changes from opening inwards to outwards (and vice versa) - it remains stuck on the door command. It will not allow me to select any other commands. This is in working plan view. Also, once this has started happening, if I move into a 3D camera view, moving the mouse now only rotates the plan instead of allowing me to execute any other functions such as zooming in etc. I am using a brand new PC, with all drivers updated. X12 is running on the same PC without the same issue. The only fix I have found is to close and re-open X13 but then, the same problem occurs after approx. 15 minutes every time.