Have you tried this trick? I just tried it for the first time this weekend and it's the only way I'll be cooking my corn on the cob in the future.
Boil your water
Add a 1/2 to a stick of butter
Add a cup of milk
Boil your 4-6 ears of corn for 8 minutes
Ta da! You have fabulous tasting corn on the cob and you don't need to add butter or salt at the table.