Yes, ballasted loads do strange things when hooked up to meters (take a look at a spectrum analyser and a sine wave graph on a multi ballasted circuit some time - ugly business). Double check your readings, then ask yourself a few questions...
Is there a problem with the lighting performance? (i.e. a slow starting ballast, cycling or super bright lamp, etc.)
Which reading (12A or 14A) matches the expected draw of the lighting?
If you take a few fixtures off the circuit, do the legs level out?
My guess is that you'll find one or more of the fixtures to be your culprit(s). Once narrowed down, a ballast change out (or two) may be in order. Either that, or the wiring to/from a particular fixture is the answer.
Good Luck!