some HTTP servers are incorrectly configured to serve up WMA
files as text/plain.  if you're interested in mirroring a
site that hosts WMA files with httrack, I would suggest
looking at the --assume option.

httrack <http://www.somewebsite.com/> --assume wma=audio/x-ms-wma

then again, I've only started using this app a couple of
days ago, so maybe someone else might have a better solution
to your problem.

Jeremy