Help! For some reason, whenever a circle is drawn, masked, or used as part of a effect & preset, they are skewed. I.E. the default is not a perfect circle. Even when I Shift+drag the circle, it stayed skewed. I have no idea why this is happening. I am still a beginner with AE, however I am fluent with Illustrator/PS/Ind and I've never had this problem before.
Without you telling us anything about your composition I will be willing to bet that you have chosen a non square pixel format and that you have not enabled Pixel Aspect Ratio Correction in the Comp Panel. It's the little box with the double ended arrow just right of the Active Camera (3D view popup) and the Select View Layout drop down menus.
My advice would be to change your comp settings to the square pixel equivalent for the frame size you are working with. You will be far better off in the long run, even if you are planning to distribute on SD TV or DVD. All other delivery formats from Web to Cable to theatrical projection are square pixels these days. Only camera originals may be rectangular pixels.
Thank-you Rick Gerard! Your answer/advice solved my problem!