I can only record a certain length of video at a time. If it's on HD, I can only record around 19 minutes of video. Even though it says 19 minutes, it only let's me record 27 seconds! If I have it in TV video, it tells me I can record 43 minutes of video. The battery is charged. I have a 4 GB SD card that we bought. How can I change the length of video I can record at a time? Is there a way to let me record as much as I want without limitations?