Weird <Equivalent> Problem in XSD

Greetings,

I am having this weird problem in XSD. Here is a simplified situation…

Supposedly I have this schema on my pc
Structure A

Node
<Equivalent>
<B:Node>
@b
<C:Node>
@c
<D:Node>
@d

*wherein NodeB, C and D are subclass of Node A

When I map a value to @b on my pc using BiztalkMapper. it works well…

but when I moved it to another pc, it has a different structure
Structure B

Node
<Equivalent>
<C:Node>
@c
<D:Node>
@d
<B:Node>
@b

so it will create an error because on my pc, it was on the first node where I mapped the value but here it was now on the third node.

Why is this happening? I tried it to moved it to different computers so far 4 PCs are Structure B, and 2 PCs are Structure A. Why is this happening?

Hope you could help me out.. If there is something not clear, please let me know.

I would really appreciate your help.

Thanks