New Document From 'New blog post' template is always dirty.

[Weipeng]

Hi Experts,

I have a question as the follow.
Steps:
1. Start Word 2007 app.
2. New Document From 'New blog post' template.
3. Modify this doc and save this file as docx format and called "Doc1" on
your desktop.
4. Close it.
5. Open this doc.(Don't modify any)
6. Close it.

Result:

The prompt " Do you want to save the changes to Doc1" was shown. Actually I
don't change any.

Could you tell me it is a design or bug for word 2007? Any workarounds?

Thanks in advanced.