Problem after "Duplicate Special" and "Mesh -> Combine"

[siub]

Dear all,

I have mae half of the face of a character and then use duplicate special with default settings to make the other half. Then combine the half using "Mesh -> Combine".

When I try to select one vertex or the original half and press "W" to translate it, the corresponding vertex of the duplicated half was automatically selected (highlighted in white colour) and they will translate together.

I'm sure I only make it as "copy" but not "instance". I have tried the same operation on my notebook but it works. What's the possible reason?

Thanks.

[stantang]

You might have the "reflection" on with the select tool.

[siub]

Thanks a lot!