thing's that happened was the scale of the model that i exported back in to maya was not the same size as when it was originally modeled... (it was modeled in maya,... then imported it in to modo to do the blendShape...)
when i imported back into maya,... the scale was already 0.5.
some of my colleage told me to try to scale it into 0.01 in maya. well,... it looked ok,... but when i try to blend multiple shape together at the same time,... some of vertex looked abit off from where it's originally is.
so,... if anyone of you guys has experienced this,... pls. tell me about how to figure it out.
ps. it was exported in the maya ascii format (.ma)