Yes I have noticed it - when those yellow messages disappear the contents of screen is shifted left. When a level is finished I wanted to display next level's number and description using yellow notification but due to this bug I could not do that. This is however an SDL bug, not Mokomaze's one. Mokomaze refreshes only the areas that have changed since last frame. It could refresh the whole screen every frame but that would be quite an overhead and performance penalty and this glitch would be still visible during one frame. This is a minor issue and I am not planning to correct it.