Are the MTS files AVC (AVCHD) w/ the H.264 CODEC?
What version of QuickTime do you have installed?
Sounds like the Revert to Trial bug. If your New Sequence dialog only seems to be showing a handful of presets (noticeably missing will be those for AVCHD and other MPEG formats), you've been bitten. Here's what to do:
1) Deactivate the software (under the Help menu in any suite application or in Premiere Pro)
3) Run the Adobe Creative Suite Cleaner Tool
5) Optionally, you can do #3 and #4 again, but it's typically not necessary
8) Update immediately from something like Bridge
It's a pain but there really isn't much else you can do.