Invis/Improved invis and "pink/moonbeam"

Okay, maybe the subject line is obscure enough, but here is my point. If I am improved invis, and someone faerie fire's me, my improved invis is gone from my list of affects. If I am improved invis, and someone moonbeams me, my improved invis is still there, and will go active again after the moonbeam wears off. That seem about right? or am I mis-calculating somewhere in here.. It's not often I get moonbeamed.