get buffer failed ffmpegx (interlace?)

[rundale]

I'm trying to encode my favourite movie Local Hero with ffmpegx. But get an error message in the Terminal window, "get buffer failed". Or to be precise hundreds and thousands of the same kind.
I got the VOB-file with OSeX, no problem.
The movie seems to be interlaced, to check de-interlace in ffmpegx doesn't help. Is there a step that I'm missing? An update of mencoder or something?
The picture is part of a screenshot from mm2c.

I've only seen this on Local Hero so far. My other DVD's don't have the stripes.
Thanks in advance for the help
And thank you Major for an excellent piece of software

[major]

I'm trying to encode my favourite movie

This is rather vague.. to which format and settings are you encoding?

[rundale]

The VOB-file was ripped with OSEX. PAL, 25 fps.
This is the only DVD I've ripped that have the stripes.

I'm using ffmpegx 0.0.6g.
Trying to get an DiVX AVI. Bitrate quite normal, about 900 for the video and 112 for the sound. I'm usually not using Mencoder.
I usually check High quality and de-interlace. I don't change any other parameters.
I tried with Cleaner 6 (on a friends computer) and I could encode but it was very slow.