A worn out butterfly knife will have just the opposite problem from yours. That is, the handles come together too close when it is latched open and they don't press tightly against the tang pin. When reconditioning an old butterfly the tang pin is usually compressed (by an educated hammer hit, don't do it unless you know how!) to fatten it up and make the knife lock tightly again.
If yours is tempermental being too tight, that is the handles don't easily come together and lock, first inspect it to see if there are any pieces out of place... most BM balisongs have bushings on the hinge pins and shims on either side of the blade. One of these could be defective and causing the misalignment and binding of the handles. If the handles move stiffly, a little drop of oil at the hinge pins might free up the bushings and help the blade seat better. Use it a little and it might straighten itself out and work fine again.
On a good knife, when the blade is locked open the tang pin sits directly in the little notches of the handles and then the handles flex to close the latch with enough force to hold the blade with no play. With a worn out knife (from many hours/days of spinning/flipping, dirt in the hinges, etc) the notches may enlarge, the tang pin can wear down and the hinge pins/bushings/shims wear thin, and start to give excessive blade play, and the opened position can wobble around a lot.
On the other hand some brand new knives need a little wear-in for the notches to be formed until the lockup with the tang pin is good. When locked open, the force on the tang pin is quite high because of the leverage from the latch at the ends of the handles. That is what makes the butterfly such a stable folding knife design.
By the way if you live in CA or MA and send the knife away they may not send it back, depending on how strictly they adhere to legal restrictions.
[This message has been edited by senpai (edited 22 January 1999).]