Error refreshing "PageNumber ()"

[Croc]

The user of Visio.getbb.ru forum found an error in Visio function PageNumber ().
The cell containing the function PageNumber (), is not updated if you move the page to the first position. But the text of the shape is updated!
To repeat this error, do the following:
Create a document with two pages Page-1 and Page-2.
Put 2 shapes on Page-1.
Shape 1 must contain a field with the function Fields.Value = PageNumber ().
Shape 2 must contain a field with reference Fields.Value = Sheet.1! Fields.Value.
In the initial state, both shapes shows the text "1".
Perform the function "Reorder page" and move Page-1 after Page-2.
Both shapes shows the text "2". That is right.
Perform the function "Reorder page" and move Page-2 back, before the Page-1.
Now Sheet.1 shows the text "1" and Sheet.2 shows the text "2". This is a mistake.
This is checked in Visio 2007.
This is a known bug?
Link to the field work correctly if Sheet.1 contains a formula Fields.Value = PageNumber () + Dependson (Now ()).
Example in attached file.