Your post indicates (just my hunch) that you have probably been getting jig fish. Truth is, jig fish come off alot when fishing marlin.
My preference is single hook rigs when pulling the jigs for marlin although you will get tons of varied opinions on this. The best most exciting and by far fun way is to throw a bait to a tailer,sleeper or feeder and watch them light-up and inhale the bait.... theres nothing much better!! Second to that would be a drop back bait.... those would be your two best bets for keeping a marlin hooked and getting him to the boat.
You must be doing something very right to have already had your share of raising marlin and getting them to bite, my suggestion would be to lossen the drags and have someone watch the jigs intently and AS SOON as a fish is spotted in the jigs or a quick zip is heard (due to the light drags) get a pre rigged and in the tank drop back out to the zone (not past it!) and be ready to do battle. Also make sure you have a swivel on your dropback so as you dont have a nasty tangled mess when the time and opportunity arises.
Good luck!!
The unknown fisherman