Bug: Why does PP Conform and reconform same video clips over and over again?

Question

Any time I click out of PP and then come back to the program from ANYWHERE (even the desktop), PP starts to conform my files.
For example, I have a very simple test project open with four 5-minute clips in it. All the files have done their "conforming." But I click outside of PP and then immediately click back inside and it starts conforming one or more of the files that it had already previously conformed. This happens every other time I click out of PP.
Shouldn't a file that has already been conformed need to go through that just one time in a project?
I'm thinking that my bug has something to do with this now since things go crazy slow while conforming. It has always done this with larger projects, but I thought it was clips that hadn't been conformed before. Now that I only have a few clips to keep my eye on, I see it is conforming and reconforming the same clips over and over again every time I come back to PP.
Here's a screencast video of the problem.  You can see it reconforms the same files over and over again. http://www.youtube.com/watch?v=uFrXk4nTpwo

Answer 1

I'll describe what happens first, as it makes the explanations of the failure cases a little more clear.
PPro generates two potential sidecar files for audio - PEK and CFA files.  The PEK file is simply a quick data pass of the audio data that allows the app to draw waveforms (ie it should be pretty quick) - the CFA files are required if the file source is either too slow to decode the audio in realtime (like some MPEG long GOP, for instance), or if there's a mismatch in the sample rate depth.  The idea is that the conform files will match your sequence's audio bitrate settings so that the app can play & mix audio in realtime.
How does PPro track these additional files?  Every file that is imported is stamped with XMP, which is how we handle metadata on source files.  XMP creates a unique ID which the app uses as a lookup value when it wants to find the PEK & CFA files that it generated for a file.  So, usually, if you have a project where certain clips constantly reconform, it has something to do with XMP.  Why? Usually it's because XMP can't write to the file.  So, every time you launch PPro and open the same project, the media file has no XMP data, so it tries to generate a new ID, so any old CFA/PEK files have an ID mismatch and the app thinks it needs to generate new ones.
Typical cases why XMP can't stamp files:
- the media file is read-only.
- the media's hard drive is read-only.
- the file itself is corrupted/malformed, and XMP takes the safe route & decides not to try to write any additional data to the file.  (I've personally witnessed this occur with WAV files captured by a Tascam field recorder.)
- someone deleted the XMP files by hand (certain media types have it as a sidecar .XMP file instead of embedded).  (Don't laugh - I recently encountered a case where people had instituted a server folder rule to delete all files on a network share that weren't .mpg. )
A workaround you can try: 
There's a preference setting to turn off injecting XMP into your media.  If that setting is in effect, PPro will not rely on the XMP ID for the CFA/PEK files.
One other note, if your problem is specific to MPEG files:  it might be that PPro isn't able to index the file properly.  If it can't index, it might be trying to re-index on each launch;  audio conforming always triggers after indexing.   So watch for it constantly indexing - if that's the case, all the XMP stuff I described above has nothing to do with the problem.  It's a side effect of something in the MPEG stream that we're barfing on.  If you do see it constantly re-indexing MPEG files, it would be really helpful to send in a sample so that we can examine the stream.
Cheers