It has happened to me a couple of times and I contacted Jennifer at Corel to find out why, and the answer was it just happens sometimes for no apparent reason and they are working on it, so relax Kirk you are not being pounced on.
children paint because they don't know they can't - so what happens as we become adults? - Me
Life is very nice, but it has no shape. The object of art is actually to give it some, and to do it by every artifice possible - truer than the truth. - Jean Anouilh 1910-87