I don't know what to tell you. I have Xbox. My Skyrim disc has practically lived in my Xbox drive for over a year. I've taken it out maybe three times (and have simply laid it playing-side face-up on my TV stand and the disc case is pretty ruined from my neglect), and accidentally opened the drive door, which lead the disc dropping to the floor a couple of times, but my copy is virtually scratch free. Ther's a few scratches that appear from me improperly inserting in into the drive, but none whatsoever from use inside the drive. That is, no scratches that appear to have been made while the disc was moving in teh drive. I've even once knocked my Xbox, with Skyrim disc inside, off its shelf where it fell 2 1/2 feet straight onto a patch of exposed bare concrete (most of my room is covered by an area rug--it fell on the part that isn't). It doesn't run as perfectly as it did before that fall--about once ever few minutes the gameplay lags in a certain annoying way--but the disc is fine. I just double checked right now in fact and I see now new scratches from the last time I hit the drive door buttong and it fell out.
As for dust: I live in one of the dustiest cities around--El Paso, Texas. We have lots of dry and windy weather, and fine particles manage to get into the house and coat everything. What's worse is my Xbox and TV (and DVR and Blu-ray, as well as my digital piano) are literally right below a window I keep open nearly year-round to help circulate the air and keep this small room cool, for myself and for all the electronics and musical instruments I have in here. I can dust thoroughly one day, but then the winds can pick up and by the next morning, there's a fine but visible layer of dust on everything again. And this isn't just typical household dust, from dead skin, fabric lint and fine particles of household paint/materials--this is fine dirt particles coming in from outside. The stuff that should be lethal to electronics, and I have a very hard time cleaning as regualrly as I should (but yes, my room's floor is littered with dried dirty electronics wipes and exhausted bottles of aerosol electronics cleaner). Yet not only have I had remarkably few problems with electronics getting dmaged by dust (aside from exterior stcraches from improper cleaning), it appears that dust is not getting into my Xbox drive (looks pretty clean in there), or at least, isn't effecting my disc at all.
So I don't know what is going on with anyoen else's Xbox, but I don't think this is a problem universl to any Xbox. In which case, there may be something wrong with your particular Xbox or Syrim disc. I wouldn't know, as I've never hd this problem. But I'm sorry--I know I would be pretty bleeping upset myself if my Xbox decided one day it couldn't read my disc and me not knowing why.
