belt feature - unequal movement

Hello,
has anyone ever used and double checked the belt feature. I have developed full suspension bicycle frame and wanted to get a graph of the pedal kickback during compression ... double checking with some other software shoed big differences.

Then I modeled a very simple mechanism with two equal sized wheels and connected them by a belt ... when dragging the mechanics the angle of movement of the two weels is unrqual .... super strange

Has anybody experienced the same behaviour and found a solution?

have a nice day
prouser/s

The following video is showing the simplified model:
<a target="_blank" href="uploads/prousers/2011-12-11_163329_belt_11-12-
<br / target="_blank">2011_21-59-24.mov.rar">2011-12-11_163329_belt_11-12-
2011_21-59-24.mov.rar</a>

I just found out that the movement of the wheels is
similar when the wheels are connected on a part which is
fixed completely, but when they are having there
rotational joint on a swingarm which is also hinged
rotationally the movement gets incorrect ... even if the
movement of the swingarm is restricted my some other
planar fixation.

The simplified Model has been uploaded here as a WF5
assembly just as reference.

<a target="_blank" href="uploads/prousers/2011-12-
<br / target="_blank">11_162842_belt_test_2_wf5.rar">2011-12-
11_162842_belt_test_2_wf5.rar</a>

Did anybody have the same experience and found a solution
to avoid the mistake?

By the way: I don't have AAX so I cannot use any "real
skeletton" but something similar.

if there is a problem downloading the files, the same files
can be found on a german pro/e discussion board:
http://ww3.cad.de/foren/ubb/Forum67/HTML/001674.shtml& nbsp;
Edited by: prouser/s

I got a reply on the german pro/e discussion board: I was
attachung one of the wheels to the axle of the wrong base
part. After modifying the movement is correct.

Thanks anyway