guile-clutter: (append score #f timeline) not working

My system:

fedora 10
guile 1.8.5
guile-gnome-platform 2.15
clutter 0.8.8
guile-clutter 0.8.0

In the doc at

http://www.gnu.org/software/guile-gnome/docs/clutter/html/ClutterScore.html#ClutterScore

I read:

"If parent is #f, the new <clutter-timeline> will be started 
when clutter-score-start is called. "

This is my line of code:

    (append score #f timeline-rotation)

but the error message I get suggests that it's expecting a null list.
However, none of the following lines of code work either:

    (append score '() timeline-rotation)
    (append score (list) timeline-rotation)
    (append score (list-timelines score) timeline-rotation)

despite each replacement for #f being a perfectly good empty list.

This is original the error message:

ERROR: Wrong type argument in position 1 (expecting empty list):
#<<clutter-score> 7fa321fc0740>

If there's a newer version of guile-clutter that I should be using, I'll gladly upgrade, but searching the web for guile-clutter [ann] hasn't turned anything more recent the 0.8 up.

Judy Hawkins