Loose frame sliders???

Hey all,
I've had my Vortek frame slides on for a couple o' months now and i notice da other day it was loose! I put sum locktite on dem mugs when i first got'em but know they're both kinda loose! I tightened dem up 2day but was wonder'n if dis was a commen thang after awhile for dem to get loose. Vibrations maybe??? I dunno... but i don't wanna be doin 80 and have pop off and my engine fall out my baby. Any help, thoughts, knowledge, suggestions are welcomed! Thnx!

I'm sure something is made for that problem if it is a common one. If all else fails, a standard lock-washer will work on just about anything.