Visio master style and functionality ignored when used in drawing

[Markhor]

I'm using Visio 2010 and I've created a new Master. The master contains a central shape and a few shapes attached to it, with shape data for each separate shape.
The width of the central shape depends on the value of one of the properties in the data sheet.
The position of the other shapes depends on the position and size of the central shape. Whether each shape is shown or not also depends on the values of the properties in the data sheet of the central shape. I do all of this using basic formulas in the shapesheets of the several shapes.
Off course I also gave my shapes some style (line type, color, rounded corners, ...)
When I use this master as a shape in a drawing, the style is ignored (rounded borders are gone, line type is reset to standard lines ...) and the resizing functionality won't work. However, the colors of my shapes is intact and the show/hide functionality keeps working.
My questions:
1) Why is part of the functionality not working when using the shape in a drawing?
2) Why is part of the style ignored?
3) Why can't I edit the master once I saved it as .vss file, closed Visio and reopened it?
Thank you for your time.

[aledlund]

what are the chances that you sill have a copy of the master that was being developed (i.e. a downlevel version) in the document stencil? That's a common issue when developing new shapes.
al

[Markhor]

It seems that I have to add the shape to my shapes, create a new stencil and open the shape in the new stencil. Then the "Edit Master" menu item is enabled again.
I also found out there was a theme applied to the drawing. That's why my style seemed to be ignored. Once I removed the theme, everything looked as expected.

My big question is still: why can't I change the width and position of my shapes depending on the shape data.
In Sheet.5 I set the width of my shape like this:
Width = Prop.items*5

In Sheet.6 I set the position of another shape depending on the size and position of the shape in Sheet.5
PinX = Sheet.5!PinX + Sheet.5!Width*0.5
PinY = Sheet.5!PinY + Sheet.5!Height*0.5

The width of the shape doesn't change when I change the "items" property in the shape data window. Therefore the other positions don't change either.

Any idea why?

[Markhor]

Found out the last part too!
Apparently you need to use =GUARD() around your function that calculates your size/position. From then on, everything worked perfectly!