So I'm having a bit of a problem. My whirlwind seems to randomly not be costing 30 rage. I was at 31 rage while grinding (27%, 31/120) with unending rage glyph and couldn't use whirlwind because "not enough rage". When I attacked a bit more and got to 51 rage then used whirlwind it took me from 51 to 18 rage. So I'm wondering, did they stealthily increase the cost? Am I missing something?