consider this..

last session i shoved the nut flush on the turn and was called by a set, which rivered a FH.

I lost 1 and 1/2 buyins on that hand, or $15. had i won, i would have 3 buyins more than i had after that hand. so I'm currently down $15, and my ev is plus about 12.. difference is ~2.5 buyins over a single hand.. so the stat can get way out of sync over 4-5 rough hands.

likewise, if you're playing badly you can run really badly, in that you might fail to suck out on your villains many times. when this happens you will lose a substantial amount but you AIEV will gradually creep up above your winnings because you had equity in the hands but so far havent won much of it..

I'm sure you can see that this stat will take A LOT of hands to even out.. so dont pay a huge amount of attention. though you can use it as a guage of whether there may be some things to check on in your last session, as there is usually a learning curve involved in why the figure is the way it is.