Mar - from San Diego, CA
As a cake bakes, it natually shrinks a little and pulls away from the sides of the pan; this actually makes removing the cake from the pan easier. The only issue I can think of is maybe you're cake is over baked. Make sure to check your oven temperature with an oven thermometer for accurate baking. Have you recently switched to a new cake recipe? Keep in mind, different recipes shrink more or less in the oven. This could be causing your problem.