Sometimes it takes awhile for someone with the time to look over a capx to get to it. Work, life, etc... tend to take precedence... don't worry, I am sure someone will get to look into it... usually I find that it has to do with the overlap of the solids or the shape of the collision polygon. If you draw a circle in paint, or something else and save it as a png with transparency and import it as your sprite, do you get the same behavior? Drawing your collision polygon in Construct still tends to have corners instead of real round edges...