Thanks for the screenshot.
Hmm. I don't recall any other reports of a problem like this with MTS files. [Just today I was working on a similar issue with P2 content, but it was limited to spanned clips. Hence that question...]
First thing I'd try is to clear the media cache files, at least for the affected clips. You should find those files here: C:\Users\<username>\AppData\Roaming\Adobe\Common\. If not there, then check Preferences>Media.