Most of the known bugs revolve around things that aren't sufficiently
error-checked. Here's the biggest examples:

* If you use the Internet with dcd, to download track lists from the CD
  Index, who knows what could happen. Not everything is checked as well as
  it could be. (This is even more true now, since there's enough code in 
  the strangely-named "libmusicbrainz" that I can't comfortably wrap my
  brain around it all. And it does all the network stuff now.)

* The `quit' code, to inhibit the normal exit of dcd, isn't thoroughly tested.

* More than a few people have reported strangeness with the `info'
  command, reporting the drive is not playing when it clearly is.
  Unfortunately, some (many?) CD-ROM drives don't properly support the
  status-request command. I've tried to work around this, but the new
  strangeness isn't any better (for many people, dcd will report the CD-ROM
  is playing when it isn't). You can't win.