canon hf g10 - filming limitations - help

Hello,

I made yesterday my first long shooting and today when playing it on my pc I realized that the camera just broke the filming two times at 11min21sec and one time at 11min 35sec and went on filming in a new file. Why didn't the cam went on filming on the same file? How can I avoid this?

Can it be because I was changing AF to MF and the MIC LEVEL during filming?

Thanks
Nuno