Assuming your '08 has the same door as mine, the door is made by PTL Engineering. You can find them by searching Google or whomever. It is a Pos-a-loc system for holding the door open. At the top there is a spring loaded cam that rotates to hold the door open. Those often get bent if the wind catches the door and slams it open. The cam is connected to a cable that is attached to the door latch mechanism to release it. Sometimes that cable needs to be adjusted.
Get on a ladder and look at the mechanism on the top of the door. If you see that cam you might want to lube it and see if it is just stuck. I had to replace mine as the shaft was bend and binding, and cost somewhere in the neighborhood of $100 for the whole mechanism. Replacing it is a DIY project, or it can be. If you need to replace it they will likely ask the brand of coach and model year. For my year they wanted to know how many screws were holding the bracket on the door frame.
Have fun as you discover all the little things involved with these coaches!