In recent daily builds for the iPod mini 2nd Gen, I have been experiencing a codec failure for all ogg vorbis files. mp3's seem to work fine.
I first experienced this problem after updating to a November (around the 24th) build and at that point hadn't updated since August 7, 2006. I.e. the August 7 build vorbis worked and sometime between then and November, something broke. I have tried the 12/22/2006 build and it's the same problem.
I've tried using the codecs in the August 7 .rockbox folder with the post-November rockbox.ipod build, but that doesn't work so I'm guessing that it must be something in the kernel.
Not the most clear bug write up... sorry. What else can I give you to help diagnose this?