Recently in Blender 2.75 I've come face to face with an inability to select the proper faces, edges or vertices in edit mode individually.
Selecting everything with the A button is no problem, but when I right click on a vertex, face, or edge in their respective selection modes, there's no orange highlight and no manipulator around the selected face/edge/vertex, which means I have no way of selecting an individual mesh piece in edit mode.
I've even tried the lasso tool and selecting stuff by pressing the C button and clicking.
I didn't have this problem until I changed my Intel graphics driver to display color in 16 bit. Except I only changed it to fix another problem in blender which made the viewport lag one step behind every action, like clicking on an object or dragging or moving something around.
I'd love to know if there's any way to fix this problem and if there's still a way to keep blender from lagging like it did before. I look forward to seeing your answers.