Who can help me?

There is a fine XYZ function addon and I tried to give it a GUI with several predifined

Strange result: if activated from a text-window it works (partly, at least no errors, behavle that complex values cannot converted to float, if there are negative bounds …)
but activated as addon it fails mostly allways

The use fo bpy.context.scene behaves rather strange.

You can get the code here: http://www.petergragert.info/pmwiki/pmwiki.php/Animation

Is it a ‘hidden’ small bug?

Who shed the light on it?