mine doesn't do any glass dancing unless she sees me coming with food for her...I should be saying "him", because now that he's healthy he's pretty clearly a guy lizard, but we're just so used to saying "she" and "her".
Anyways, I was wondering if maybe it had something to do with substrate, cage furnishings, or length of time being in captivity. From the information we could obtain, my uro is about 6-8 years old now, and I hope she/he has many more good years to go. What's your setup like? Mine is fairly simple, with dirt substrate (a thin layer) and a nice hiding "burrow" (it's made to sort of mimic a small burrow) that doubles as a basking site. The fake burrow is fairly big, so he/she has the ability to thermoregulate inside of it. Also, the tank is small compared to what he/she should be in (it's only 48"x13"x13"...hopefully next week I can get going on my 4'x2'x2' stacking cages), and I would have assumed she...he....it...would be glass dancing all of the time, but he only did it the day I put soil in, and only for a minute or two.