Usually, the "buffer Overflow" error happens when the recorind environment is too loud - or there is too much vibration - for the camcorder's internal disc drive to deal with.
This has to do with the way hard disc drive heads "fly" over the platters when writing or reading information. The vibration can cause the head to hit the platter and crash the drive so the camera's sensors park the head. The assumption is that the small buffer (flash memory) in the camcorder can store *some* of the video and the vibration will go away allowing the hard drive to start working again. When the hard drive does not start working - because the vibration is still there - , the buffer overflows and can no longer temporarily store video data.
The best resolution is to remove the camcorder - the hard drive - from the source of the high vibration. If you are at a loud concert, then no recording. I've seen others try to use hard disc drive camcorders at rock/pop concerts, marching band concerts, car races and other activities with loud engines... even cheering people at sports activities can cause "buffer overflow". This is one of the main reasons hard disc drive camcorders are not recommended (as much as the manufacturers want you to buy them because they can record a long time so that must somehow be more convenient).
Another way around is to use flash memory. The record time will not be as long, so carry extra, blank memory cards.
The last way is to turn off the drop sensor. It is what triggers the drive heads to park. Warning: doing this can cause the heads to crash and the camcorder will be useless/broken/dead. DriveSavers loves to charge people to get data off these cameras. Your credit card limit needs to be high and available.