[Five]

there was a discussion about this a month or two back... I don't believe there's any way to view/edit realplaygain tags, they can be added at the time of encoding and that's about it (for the time being). If anybody knows how to view/edit them, I'd love to learn.

the "mkwACT md5 signature" is a simple wholefile md5 hash which can also be generated by many other progs (such as md5summer). This is a "dumb" sum because it is based on the entire file, so when you run one on a FLAC it calculates based on the compressed audio together with its header. So the little bit of information contained in the header for realplaygain (probably 1k) is what's throwing off the verification, whereas with ffp & st5 the hash is generated from the decompressed audio. ffp & st5 are subtlely different but the checksums aside from formatting will be identical for any properly encoded FLAC set. The advantage of st5 over old wholefile md5 is that since it calculates based on the decompressed audio only it will show the same checksums even if you reencode at a different compression setting or even to another lossless format. md5 is sensitive to any change in the compression and/or header and can be useful (as you've found) for detecting changes in the header when all else fails.

hope that makes sense, I'm still on my 1st coffee...