Help me Big Bob

I tried using the ax, as you suggest, to split some 12" oak, probably white oak, and some 8" pine (both about 16" long and about half-way dry). Even though I tried "tipping" the head a bit before impact the thing sticks something terrible.

The ax I used is a double-bit 5 pound, 10" bit-to-bit and 4.5" across the bit. It is reasonably slim but is not what I would call a true "felling ax". It is quite sharp and is my third favorite ax (#1 being the one that stays in its leather sheath unless conditions are absolutely perfect).

Similar wood hit with my 6# maul flies apart, usually on the first hit. And, if the maul does stick, it is not near so hard to dislodge as is the ax.

Is there something I am missing? I'd really like to be able to split effectively with the ax. Should it be a different type of ax? Is being sharp a disadvantage?