* Sound may not set volumes correctly.

  It is possible that volume of sound effects does not scale properly 
  with distance from the sound source.  It is also possible that sound 
  effects are cut off at the wrong distance. This needs further 
  investigation.

* A small number of Doom bugs are almost impossible to emulate.

  An example of this can be seen in Ledmeister's "Blackbug" demo which 
  shows a bug that relies on the memory layout of the Doom executable.