problem with "frame"

[Katsumi Matsumoto <katsumi@xxxxxxxxxxxxx>]

Hi.  I am trying to make some animation graphics.

Ferret aborts when I issue the following cammand:
repeat/l=1:20 (fill variable; frame/file=movie_frame.gif)

It's the frame bit that is problematic.  Without it, I can see a rapid
succession of 20 filled pictures.

The error message that ferret spits out is:
unknown_program: unable to translate window coordinates (0,0)

Can anyone tell me what's happening?  I'm running ferret 5.51 on a linux
workstation.

Thanks,
-Katsumi