I have a Sony HDR-NX5 and

I have a Sony HDR-NX5 and have never encountered this problem other than when the camera switches from drive A to drive B. Your issues may be arising from the class of card you are using, and should not be lower than Class 10. I have heard of these problems when using a lower class card, which cannot write fast enough to the card. I am not an expert on this and perhaps you should experiment with higher class cards. Hope this helps.