It's kind of funny that you say that because I've noticed that they don't stick as well to the trebles and those big single hooks. I've not only noticed it with halibut and seabass (since we discovered the fastrac) but I've noticed it ever since I started fishing. Unless they're hooked by all three points it seems that the hooks work themselves loose easier. I've actually been contemplating sticking some single hooks on the fastracs.
Also, for everyone using the fastracs you should remove the center hook. Not only will you not injure the fish as much but you will have less of a chance of popping your tube or hooking yourself. With halibut it seems about 80% get the back hook and about 20% get the front. With white seabass it's more 50-50. When I first started using it I had the center hook on and none of the fish were hooked by it - it's a waste - trust me. Also, be careful netting fish because that extra hook dangling around will catch the net and if the fish flips out you'll loose it (I learned this the hard way).
Pete
You can't catch tomorrow what you kill today - please practice catch and release.