Help Have to use home button to answer phone


When I receive a call on my Captivate, I have to use the home button to answer. There is a big pretty button on the left that has a green dot with a phone icon that you would think would answer it but it doesn't. Is there a setting somewhere, or a fix for this?
Red button on the right with the phone icon hangs up, so you would think the green button would answer.
I think you're supposed to drag the green button to the right to answer a call? Or maybe you're already doing this, but I found that just pressing the green button won't answer, you have to drag it to the right.