[MPlayer-users] mencoder: yellow becomes blue

[dvdrip]

Hello.
I created my first animation today with mencoder.
But the colour yellow becomes blue somewhere... at least it's not yellow when 
I play the movie with mplayer.
Oh, perhaps it's not blue, it's more lika a combination of blue and green.
I will send you the 300 kb movie upon request.

The command used:
mencoder -mf on:w=320:h=240:fps=25 -ovc divx4 -o q.avi \*.jpg

Any ideas why this happens?
Version MEncoder 0.90pre8-2.95.4

Best wishes
Gunnar