Energy Regeneration Error -- Expertise?

I've been having some problems with my energy regeneration lately. Occasionaly, when using a skill, my current energy will add the number of energy being spent (based on expertise) double, then go to zero, and then it will regenerate twice as slow.

Example:
Current Energy 6
Expertise 11

Dual Shot -> 6 + 6 -> 12 -> 0.

Now, with my three pips of energy regeneration, it takes six seconds to regenerate one energy. Has anyone else been experiencing this problem?

P.S. I realize I should had searched first, but I decided to just post it after writing it all up.

I've noticed the Energy that's supposed to be subtracted added, like you said above, then subtracted normally, but I'm pretty sure I don't have regeneration problems with my ranger.

I'll check my energy regen a bit more carefully and post again if I find anything.