Outdoor Power Equipment and Small Engines - Drive belt woes

I have a fairly new Cub Cadet model LT 1018 - Series 1000. It keeps ruining drive belts (part number - #754-0461). Is there anything that can be done to help this? It always comes off the movable flat idler pulley and gets caught above it. :?:

I'm not familiar with that mower, but is the flat idler in line with the rest of the pulleys? It may need to be bent or adjusted up/down to get it in line with the other pulleys. If not, is there a good flange on the edges of the pulley? There should be. It should be enough to keep the belt from being able to ride off the pulley. The plastic ones often wear off. Does it have a belt keeper on the pulley to keep it from coming off when the tension is relieved? If so, it may need adjusting. If not, there probably should be.

Cheese,
This mower has a hydrostatic transmission...the drive belt has constant tension on it at all times. The flat idler pulley is metal, has raised edges on it...but doesn't have a belt guard. There is a local Cub Cadet dealer who says there is a kit made especially for this problem...and he conviently says they can install one for $65.00.

You gotta love it. " We don't have a problem but happen to have to make a kit to fix the problem we don't have".

Yeah, what goldstar said. If it's an inherent flaw in design that they have since revised, then why in the world are they charging you to fix it??! They designed it wrong, and they know it, so how's that your fault?