Guy Muse over at The M Blog has written a very thought provoking post called, Was this Man Biblically Baptized?, concerning the IMB recent guidelines for baptism. Where he shares the story of a man who was baptized, but in a way that does not meet the very guidelines the IMB has setup as a test for future missionaries.
I highly recommend you read his post and answer for yourself the questions he ends with:
WAS THIS MAN BIBLICALLY BAPTIZED? If he was, why are we setting up standards and guidelines that go beyond what Scripture teaches about believers baptism?