can't get avi to mpg

Got 4 files I want to convert to dvd from mkv. They were dual audio and no program I used would allow me to choose between audio, so I used mkvextract to get the audio into aac then convert to wav. That worked fine. But now I have trouble trying to open the video for the mkv file. I tried converting to avi but nothing.

TMPEG says unsupported format. I tried moving th emultimedia setting to highest priorty but nothing still. Virtual dubmod tell me it can't locate dx50. Its a divx codec so I reinstalled divx and still nothing. Other programs tell me it has avisyth problems(dvd2vcd) and can't encode with it. avi2dvd gives me problems:

avi2dvdlog-

[11:58:03 PM] Start creating avisynth script ...
[11:58:03 PM] Avisynth script created successfully !
[C:\Documents and
Settings\Administrator\Desktop\9\Avi2dvd_temp\Avisynth
_Script_File.avs 180 Bytes]
[11:58:03 PM] Bitrate used : 8000 Kbpps
[11:58:03 PM] Start video encoding ...
[11:58:04 PM] Video encoded successfully !
[C:\Documents and
Settings\Administrator\Desktop\9\Avi2dvd_temp\Encoded
_Video.m2v 0 Bytes]
[11:58:04 PM] Job NOT Done. There are warnings ... Find
at the log file the 0 byte generated file to focus where
exactly the problem appears

-end

I get that no matter what codec I use. I tried using the original MKV and say it can't open. I just need a way to get this avi file to m2v so I can combine it with the wav file and make dvd.

Gspot says I can sucessfully render the file. Avicodec tells me its divx also.