Video grabber error: SampleCB() buffer size do not match

i’m using an ImagingSource gige camera with resolution 16001200. Amcap can grab image from it. but video grabber fails to grab image from it with Error: SampleCB() - buffer sizes do not match. i found a similar post about this error. but in that post, they just change the image size. for my case, i’m sure that my camera is 16001200 and i’m trying to grab at exact the same resolution.