AutoCAD Inventor :: Replace Family Template - Import Part Is Invalid

I've got an error everytime I try to replace a Family template in my Content Center (I work with Inventor 2011).

I try with a simple part.  Here's the steps:

1- Create a simple part (cube with Width, Height and Depth parameters)

2- Create an iPart with 12 members

3- Publish the part in the Content Center

4- Modify the part (add a column in table)

5- Save

6- Open Content Center Editor and click on Replace Family Template

Got the error: "Import Part is Invalid".

I tried "Save As" instead of "Save" and got the same result.