Unable to record multiple programs at once.

I just got U-verse TV installed in my apartment. I have to DVRs total (one in my bedroom and another in my living room), and when I try to record two shows that are set to run during the same time, I receive an error and a conflict message saying that I have to choose between the two shows. Am I missing something? I thought that U-verse could record up to 4 shows at a time? If this is the case, why am I unable to do so?