Potatoes are not soft

Tonight I made a recipe that I have made many times in the past: Italian Sausage and Potatoes. Normally, I cook this for about an hour in a Dutch oven and it comes out great. Tonight, I made it in a disposable pan because I was taking it to a pot luck dinner. After an hour and a half of baking, the potatoes were still crunchy! :frowning: Could it be the type of potato I used or is the baking dish going to make that big of a difference?