I'm trying the demo of Premiere CS5, and among the various things I'm discovering there is something a bit strange. When importing a clip to Premiere, the date of that clip was changed in the Finder.
So, I wonder if there are situations where clips are modified, and non-destructive editing of the original clips is limited to some, but not all functions.
If you have the Write XMP ID To Files On Import checked, then a single piece of metadata will be written to a file when it's imported. If you want to turn this off, disable that preference.
The purpose of this preference is to tag files so that Premiere Pro and other applications can keep track of assets. One of the benefits is that the media cache database can tell whether the file has already been processed for the media cache.
Thank you, Todd. If so, I'll leave it turned on.