his problem isn't the slider. The slider is doing what it needs to do. His problem is that when he changes the slider, it changes the texture, as intended (or it should) but if you log out, and back in, the texture will be at the default until he opens and updates the slider.
He simply needs an onload in his initial frame to get the variable when the player logs in. The slider only needs to change it if they plan on changing it, not change it on game-load.
On a side note, I could easily fix your issues as posted and post the updated code, but I prefer not to. The only way for a person to learn (or at least the way I learn best) is by breaking it, and fixing it yourself. So I will kinda nudge you in the right direction, and help you when you need it, but anything more than that might hurt your own learning process