[quote=Jim Sachs;106318]It sounds like you bought a 2.6 upgrade Key, which upgrades from 2.0 to 2.6. Contact Prolific Customer Service and they'll try to straighten it out.
Same thing happend to me. I've been using Marine Aquarium 2.6 for quiite a while. Bought the 3.0 BETA upgrade for $9.95. When I try to register with my new keycode, program asks me to enter a valid CD (which I don't have, of course). Ad for upgrade, however, says product will register with a valid CD or keycode. Now I'm out $9.95 and still cannot register the 3.0 BETA. I sent a message to Prolific.