I’m having a similar issue, I thought I’d add it here instead of starting a new topic. I’m in the process of migrating from wp.com (openpandora.wordpress) to a privately hosted MU (not my own server). I’ve entered my API key, and I’ve got the message:
The API key “**********” belongs to the WordPress.com account of “gruso”. If this is not your account, please re-enter your API key.
That is my account, but it seems to have no effect. When I click on “Add to wordpress.com account” I get the following message:
Error from last API Key attempt:
The owner of that API Key (MU owner) is not on the access list for this blog (*********). To be added to the access list, you must contact support.
The username I’m using for wp.com and the MU are different, but the email address is the same. I don’t know if this is a factor.
Any help appreciated!