API key doesn’t work for wordpress.com stats

Hi guys, I desperately need some help on these. I had uploaded and activated the ‘automattic stats” plugin and after I had entered my API key, the following appears:

Error from last API Key attempt:

The owner of that API Key (malaudy) is not on the access list for this blog. When this blog was registered, ‘s API key was used. To add you to the access list, must visit this blog’s stats dashboard page and use the form at the bottom of that page.

The problem is, I couldn’t find any access list or forms whatsoever. Does anyone knows how to solve these problem?