[Aleksandr Pantyukhin]

OK. there is one more solution : Converting MTS file with VLC player.
It takes not much time since you have it done 1-2 times!
1. Open VLC (you can download it free)
2.Click: Media-Convert
3. Add your MTS video file
4.Click Convert/Save
5. In Setting: select profile:Audio – MP3(MP4)
6.Click icon (screwdriver) of Select Profile- Encapsulation and select MP4/MOV
7. In Destination: browse for your folder where you keep the videos you work with.
8. In File Name: Type a name with exstension .mp4 (It is important! otherwise CS6 would not import your audio file, do not know why).
9. Click Save and Start.
10. Open your Destination folder – you will see your new MP4 file (actually it is a video file, but there will be Audio content only!)
Done! Now you can import it as audio to CS6 and place it in Audio Timeline under the original MTS video (which has no audio)

[Aleksandr Pantyukhin]

I found a solution (kind of…)
1. Import the clip into CS5.5
2. Do not edit it, just export it to a folder. BUT Audio ONLY!
3. Open SC6 and import the same clip into the new project. There will be no sound of course :(, drop it on the time line.
4. Import the audio file from the folder into the project. And drop it
on timeline. It will perfectly fit the original video clip. Done.