Here is the breakdown for your appliance:
Model MSD2957AEW
If you look at the the fountian breakdown they do show a barrier (number 21) in the picture, the fact that it does'nt come with the new board may indicate the manufacturer expects you to use the old one or if lost purchase a replacement.
Click here for barrier:
Part Details - MAYTAG Barrier, part number: AP341132
Click for control board:
Part Details - MAYTAG Control board, part number: AP341131
Aslo make sure everything was mounted correctly and no othe damage exists. The plastic has a history of warping and may affect the position of the parts.