decoding error 0x0235 (bad main_data_begin pointer) at byte offset 0 error

hello.

If my callback function output() return MAD_FLOW_CONTINUE, I get no error.
But the same function return MAD_FLOW_STOP, then I get error of title.

This error is not always occurred.
1st frame of function decode(), error has not occurred.
1frame and 8bytes of next frame is not broken.

I think I use the wrong way. but how wrong,I don't know.

Please advice me how to use libmad with output() return MAD_FLOW_STOP.