Ore Veins

So this has been bothering me for quite some time. My 70 hunter had skinning/mining. I recently ditched skinning and picked up Eng. As I was working to level Eng up, I needed a lot of copper ore. What I found is that in many of the starter zones (e.g., Durotar, Mulgore, etc.), I could only ever tap a copper vein once before it disappeared. Every single time. Didn't matter where it was, if it was existing, or if I waited for a respawn. Always only 1 tap. As soon as I venture further out (such as Barrens), now I get multiple taps.

This can't be the standard, because lowbies picking up mining early on (I would assume) would be getting multiple taps on a vein. So has anyone heard of this? Did Warmane gimp the veins for 70's to deter them from over-farming the starter areas?