Unless something changed on the last update perhaps, anti-skid isn't implemented yet, so mashing the brakes will eventually produce skidding. From your description, you may be using your brakes too early. I personally use aft stick and air brakes to get myself well bellow 100 knots before using 2 second stabs at the brakes to avoid skidding. I'm no expert, but I'm pretty close to 100% landing success unless its some crazy windy rainy day in the Caucusus.