PIPING DESIGN?????? Please help

Hi,
I am a 3d design draftsman from Sydney Australia.
I have created my own pipes (as per australian standards, inventor does not have them) and completed the correct steps in the ipart, pipe authoring and publishing processes to have my own styles in the piping design application for inventor professional 2008. every step of creating pipe runs works with my new pipes and fittings except for one thing.

Inventor Pro 2008 allows you to change the size of segments of pipe runs. this works, however for the pipes I published do not change size correctly, though it defaults to the length specificed when creating the ipart. This seems strange.

I am completely stuck, I have no idea how to fix it, the help desk people here do not know either.

see the image attached.


can anyone help?
cheers
Mick
michael.anderson@glv.com