hey just used this program today MKVToolNix 2.0.2
it is a free program
it converted my mkv files to avi in about 9 seconds
then i was able to burn them to dvd and it worked great
just add file to convert and save output file as avi
just give it a try
http://www.bunkus.org/videotools/mkv...0.2-1.i586.rpm
enjoy
cheers
chapps