Apps not transferring to ipod touch

I downloaded a few apps on my computer and transfered them to my ipod. All but two transferred successfully. It says the other two couldn't transfer because my computer wasn't authorized. I've had no problems with other apps, so obviously my computer is authorized. I even deauthorized it and reauthorized it again but it still didn't work. I paid for one of these apps, so I would like to get in on my ipod. And yes, they are compatible with the ipod touch.