on updates MDB2 returns numrows instead of a result

Doc says inserts and updates return the number of affected rows instead of a result: http://pear.php.net/manual/en/package.database.mdb2.intro-query.php

so ... yet another difference between PDO and MDB2

cc @schiesbn @Raydiation @bartv2 @DeepDiver1975 @icewind1991 @MTGap