Confusing error messages for switch

public class CaseBug {
    public static def main(args:Rail[String]!): Void {
       val aByte = args.length > 0 ? Int.parse(args(0)) : 2;
       switch(aByte) {
       case  0 as Byte: Console.OUT.println("A!"); break;
       default: Console.OUT.println((aByte as Byte)+" not legal.");
       }
       switch(aByte as Byte) {
       case  65: Console.OUT.println("A!"); break;
       default: Console.OUT.println((aByte as Byte)+" not legal.");
       }
    }
}