I had this problem also. Assuming the door locking mechanism is the same on your 2007 as it is on my 2006, then the fix is very straight forward. Remove the vinyl covered panel that covers the door locking mechanism; there are four screws attaching it. There are also two screws holding the deadbolt lock in place and two screws holding the black handled latch at the bottom.
Since this happened 6 months ago, I don't remember if you have to remove all these screws or not. Remove as many as necessary to expose the interior locking mechanism. Once the interior locking mechanism is exposed, its operation is fairly obvious. In my case, a screw had loosened, that allowed the locking mechanism to get "out of sync". Once I determined how all this "should" work, then fixing it was obvious. I would caution that you take pictures of everything as you take it apart so that you know how to reverse the process to put it back together. Also, be careful about losing any screws or allowing any parts to separate without first taking a picture of how they fit together. I make all these cautions, because the interior locking mechanism looks like a Rube Goldberg contraption.