CS5 Issues importing media on new PC

On my old laptop everything ran fine, but since installing on my new PC I'm having some issues...

Mainly I can no longer import MTS.

I have tried converting the MTS files as a temporary solution, but have had several issues trying this.

-when converted to MP4 there is no audio after importing. (Audio is in mp3, same issue when I tried AAC). If I convert the whole video to mp3 (with no video) I can successfully import that however.

The application is also using audio layer 5 by default, and won't let me drag clips to other audio layers.

Any tips or explanations of what's going on would be much appreciated.