Yes, regardless of wether your using glass beads, sand, Black beauty, or any other hard abrasive for that matter, it will eventually break down into a fine powder. Typically the powder will dust up the inside of the cabinet making it hard to see, do very little actual debris/rust removal because the sharp edges that do the cutting are gone, and often will also clog the nozzle (dependent upon the type of blaster you have). Once you get to this point any time you blast your working really hard to do very little cleaning when you blast. I usually leave a bit of the find stuff in mine, maybe 5% and renew the rest with new stuff. If you haven't done it in awhile it will probably suprise you how much better/faster parts start getting cleaned off again.
That all said, if your doing alot of heavy rust/paint removal, give Black Beauty a shot. It is some pretty agresive stuff. If you want to stick with the glass, give 'ground cullet' a try. It's more coarse than the glass beads and will cut the rust/paint alot faster, if that's what you need.