AoXoMoXoA, I copied your post from the 358 thread:
I have a slight flac problem that comes up occaisionally.
I import & tag a flac file, rename by properties to it's new home (Artist\Album\filename), add cover art, and run audio analysis.
OK, here is where the problem arises: I sometimes come across a file that fails audio analysis. When I test the file in FlacTester it results in "ERROR MD5 CHECK"
When attempting to convert to a wav file MC fails to convert, and dbPower results in: "Error converting to Wave, md5 did not match decoded data, file is corrupt"
Since I habitually save a backup copy before most of this proceedure (for protection until I get to run a real backup), I was able to check the original file copy that had been untouched by MC only to find it is not corrupted like the one MC had processed.
I strongly suspect this corruption occurred while attaching cover art, but that is just a hunch brought about by the fact that this often has crashed MC.
edit: Just attempting to add cover art to a newly tagged/renamed/imported album and MC said it failed to update the files/tags. I went to the folder and using "Unlocker" I found that MC had the files "locked". Once I closed MC and re-openned it several minutes later it was now able to add cover art and update the tags with no issues and much faster that it has been doing.
What operations would cause MC to maintain a lock on the files it has already finished tagging and subsequently re-written to their new location?
Hoping this helps lead you down the right path to resolving this.
Do as Jim said and install the latest build, even though FLAC isn't mentioned in the change logs. It is important that you have the same build with the development team when they try to reproduce the problem.
I tried quickly embedding cover art to a few FLAC files and it worked without problems, but I didn't try to reproduce exactly what you explained and not with a large number of files.
Adding cover art to FLAC files is a heavy process because the tagging component usually must rewrite the compete FLAC files. The FLAC tags are in the beginning of the file and the default size of the padding block is only 4 kB, which is not big enough for usual cover art fles (padding block = empty area for additional tags).
Probably the In_FLAC.dll plugin needs to use a temp file when it adds cover art. After tagging is finished it deletes the original file and renames the temp file with the original name.
I am only guessing, but here are some questions that came into my mind:
Do you have enough disk space in the file location and in your temp location? Are the files local or on a networked drive? If you access them through network what is the connection type and speed?
Do you by any chance use the Auto-importer? I wonder if it could interfere the process and occasionally lock files when it shouldn't. Or maybe an antivirus program could do the same if it is allowed to scan all possible file types.
Perhaps the Flac plug-in doesn't have all the same safeguarding mechanisms that the MP3 plug-in has (also the ID3v2 tags are in the beginning of the). I'd quess that we would see a lot of bug reports if MP3 tagging had a similar problem.