Seger v. Magnum Oil, Incorporated [10/29/99] 1999 MTWCC 67 A statute does not operate "retroactively" merely because it is applied in a case arising from conduct antedating the statute's enactment. Porter v. Galarneau, 275 Mont. 174, 183, 911 P.2d 1143, 1148-1149 (1996); Landgraf v. USI Film Prods., 511 U.S. 244, 114 S.Ct. 1483, 128 L.Ed.2d 229. The Montana Supreme Court has defined a "retroactive law" to be "one which takes away or impairs vested rights acquired under existing laws or creates a new obligation, imposes a new duty, or attaches a new disability with respect to transactions already passed." Continential Oil. Co. v. Montana Concrete Co., 63 Mont. 223, 207 P.2d 116; Wallace v. Dept. of Fish, Wildlife and Parks, 269 Mont. 364, 889 P.2d 817 (1995). In St. Vincent Hospital v. Blue Cross, 261 Mont. 56, 862 P.2d 6, 9 (1993), the Montana Supreme Court stated that a "retroactive law" is one which gives a "transaction a different legal effect from that which it had under the law when it occurred."