If you have Mike and Kelly's 2720 Manual, see page 27. If you don't, you can get a copy at
http://www.tmphotos.org/Mike%20and%20Kelly.pdf.
I had a problem similar to yours and discovered that I hadn't closed the legs properly. Once I turned the ground brackets under, tucked them under the center tab on the case, and snapped the left and right leg ends all the way in, the awning fit smoothly, all the way into the case.
I hope this helps.