I have heard that the lithiums do put out a higher voltage of power... and I do have a litium AAA in my dorcy 1AAA, which works just fine. I am not shure about the 2AA though, sry.
I use the energizer lithium batteries in my Docry 1AA, 2AA and 1AAA lights.
/ubbthreads/images/graemlins/smile.gif I also have a pair of energizer lithium AAA batteries in a modded 1AAA that now runs a Luxeon and used 2 AAA batteries.