While listening to my collection yesterday I stumbled onto a file (MP3 320kbps CBR) that was practically inaudible (it had per-file ReplayGain info applied with v0.8.3, like 90% of my MP3s).
Being the first time it occurred to me, I tried to re-scan it and received an error (Unsupported format or corrupted file); rebuilding MP3 stream didn't fix it. Without ReplayGain info I can listen to the song with no problems.
I tried the same file with v0.8.3 and I was able to scan it (same values as before) and the volume was ok both before and after replaygaining it.
If want to have a look at the file (~10MB) just ask.
Alessandro