I don't know exactly what RealJukebox was supposed to have done, I only read that this was a common problem. I assume that it was supposed to have replaced a DLL or a codec with an older version, breaking the updated Xing encoder that was included with AC.

I'll bet that it was some other program (something other than RealJukebox) which did the same thing, then. Not sure what. It'd be nice to know which file it was so we could fix it by hand.