Maya renders just sequences of images it makes no asiption on how fast they should be played thets what you need your video editting app for (the avi is ntcs speed because mediaplayer asumes that f nothing is set).
Example whan using ae set the conform rate to 18 and it wont drop any frames it will take your say so that the footage is at 18 fps even if the format says whatever!
Also in general its much better (many reasons which have been discussed to the death, so search the forums if you are interesed) to actualy render still files and compile them later, qt pro is a good quick small app for this!