"you wasted your bills" IMHO
This forum is full of AVCHD issues, In fact it would be the most posted issue by far.
AVCHD is a devil spawn format.
Somewhere there must be something that can edit it - but what.
(Sorry to be so negative but I am yet to see the value of this crappy format that makes users think they have an easy entry to producing HD movies just by buying a Consumer Camera - its a marketing hype n used to sell cameras that does not fulfill the entire promise ..)
Craig is spot-on most times, but he's missed the mark this time. Twice.
- You have encountered the dreaded oops-I-went-back-into-trial-mode-for-no-good-reason behavior of Pr. To solve it, uninstall Pr completely, run the CS4 clean script, then reinstall Pr. Others have suggested that you should run the clean script 2 or 3 times before reinstalling, rebooting between each run.
- AVCHD can produce some stunning video when shot through decent glass. Not all AVCHD cameras are consumer-level.
EDIT: I can edit AVCHD flawlessly and fluidly here using Pr CS4. Dual quad-core Xeons with 16 GB RAM on Windows 7 Pro x64. Not a consumer system. If all you have is a consumer system, then you need to convert the AVCHD to a less demanding format using the software that likely came with your camera. Then edit the converted footage in Pr. Most users that have trouble editing AVCHD natively, and then complain that Pr can't do what the marketing hype said it can do, are missing the point. Pr can edit the footage natively. But their computer hardware can't handle the demands that Pr puts on the system when it does that.