Problems on OpenSuse12.1 with a FFmpeg MSMPEG-4 v2 video

Dear all,
I use mencoder to get videos into kdenlive. With one video it works fine (it is composed of a sequence of .jpg) while the other video has major problems in the clip monitor and project monitor: When I play it from the start it works well, when I stop/seek forward/backward the video frame does not change. As if it is frozen.
I tried all Configure:playback-video driver options: no improvement.

My encoder options:
mencoder -ovc lavc -lavcopts vcodec=msmpeg4v2:vpass=1:vbitrate=25000:mbd=2:keyint=132:vqblur=1.0:cmp=2:subcmp=2:dia=2:last_pred=3 -nosound -o ExpNew2.avi Exp.avi

I have to transcode because the original "Microsoft RLE", codec does not work at all in kdenlive.

Any help?

Otherwise, kdenlive seems to work nice, many features. Thanks
Steffen