Kitchenaid Superba Selecta Detergent Drawer Stuck - Please Help

[ngraysmith]

We moved into our current house about 2 years ago. The dishwasher is a Superba Selecta Model KUDA22SWWH1. About six months ago, the main detergent door (there are two doors on this model) began sticking. The other door has worked fine. I have scrubbed the door and had some success running hot water/vinegar all over the door from time to time, but it just keeps getting stuck. Any thoughts or suggestions? Thanks!

Nicole