Problem with DocumentProtection in Word 2003 => Save As .Doc possible?

Hello,

When I create a .docx programmatically and put some DocumentProtection on it, it will work fine in WORD 2007 & 2010. But if you open the .docx with "Word 2003 (Compatibility mode) all the protection will be gone. If I search on the internet, it seems to be a well known problem. If you create a document with Word 2007 and put manually some protection, the same problem will arise if you open the .docx with "Word 2003".

I tested the same thing, by saving my .docx as .doc and then the protection worked fine!

So my question is :
* Is there a way to save you .docx as .doc with "Open XML SDK 2.0"?
* If not is there an easy way to do that without using the "Word.Application" dll?
* If not is there an easy way to accomplish the conversion client-sided (javascript/java/...)?

My programn is an C#.aspx page! I've searched the internet for days and haven't found a good and working answer :(

Kind Regards,
Frederic

* Is there a way to save you .docx as .doc with "Open XML SDK 2.0"?
No

* If not is there an easy way to do that without using the "Word.Application" dll?
Yes, there are several tools around that offer converting to .doc - I think Microsoft's Word Automation Services is one that can do this.

:)