If you can use the key to lock it, but not your fob, chances are it's the actuator.
I actually replaced my driver side actuator in my RSX over the weekend. When I pulled the bad one out, you could hear something rattling in there when I shook it. The new one of course did not have that issue.
Also, I moved your thread from the How-To section. That section is for posting How-To / DIY's, and not for tech questions