I was going to respond to your query but found the thread locked, so I'll put my comments in as a new topic.

MTS files, also referred to as AVCHD or H.264AVC, I've had no problem editing these types of video in PD8, but I'd suggest first copying the files to your computer's native hard-drive before editing. You may find them easier to handle than if they stayed on your camera's SD-card or inbuilt hard-drive(as some cameras feature these days). You could also remove the card and insert it into a card-reader either connected to your computer via USB port or built into your computer, but again it would be better to copy the contents from the card to your native hard-drive. However, having said that, if the contents are stored of a flash-drive, or thumb-drive as you Americans call it, plugging that to your computer, you could edit your content from the flash drive and store the finished "product" on your computer's hard-drive, but that's from a flash drive, not an SD card. Hope this info is of use to you.

Cheers!