Rubber band messed up after saving, closing and opening

[Jaco van der Molen]

Hi folks,

Sorry to have been of the radar a bit now that we really got things going discussing LPub3D, LDCad and all interesting stuff.
I've been a bit busy with other stuff then LEGO and LDraw... :-(

However, I got around again practicing LDCad an decided to try to model this cute little technic set:
http://brickset.com/sets/8203-1/Rover-Discovery
It has a rubber band rather typically shaped by the way it is in the model.
I tried to model this band like it would fit the model (not the way I want exactly yet).
See this screencapture video: https://www.youtube.com/watch?v=wo_lp3S9NrA
It looks nice but when I save the file, close it and re-open it, the band is totally messed up.
Doing some work on it again to get it a bit like the way it was, saving, closing and re-opening it even messes up further.

How can I solve that?
Is this the same issue that I had with the small minifig chain assembly I posted before? Is the band simply to small to calculate?

Then: how do I create a rubber band that mimics this band the way it is in the model?

Thanks.