transcoding does not work when adding an external audio track (command line)

[StR]

set avidemux5="C:\Program Files\Avidemux 2.5\avidemux2.exe"
set videocodec=XVID4
set audiocodec=LavAAC

for /r %%f in (*.AVI) do %avidemux5% --load "%%f" --external-wav "AUDIO\%%~nf-1.wav" --audio-map --video-codec %videocodec%  --audio-codec %audiocodec%  --output-format AVI --save "..\UPLOAD\%%~nf-upload.avi" --quit

This Windows (Win7) script does not seem to encode the file as expected. Instead, it saves it with the original codecs.

Any clues why? Or, better yet, - how to do it from the command line?
2.6.7 version is having problems doing  --external-wav from the command line.

[StR]

Upon further digging and experimenting, I discovered that from the command line, 2.5.6 does not understand XVID4 as a video codec (unlike 2.6.7), but instead takes XVID.
Also, it does not understand LavAAC.