WordPress API seems linked to another blog

I have my own blog: spiritual-web.com with my own API key

I also works and maintain a friends blog with their own API key

Everything was working fine until today. Now I am unable to check my blog stats using WordPress.com Stats it tells me I am not the owner of that blog. I deactivated the plugin, reactivated it, re-entered MY API key – it said all was installed and working correctly. I then click ‘Blog Stats’ on the dashboard and is tells me again that I am not the owner of that blog. Just to confirm, this is MY blog and MY API key that I am using here.

The only thing that has changed is that this evening my friend (on her blog stats page added me a user. Although I am not sure that this would have made any difference.

But her blog stats are too high and it looks like my stats have migrated over to her blog.

Can anyone shed some light on this peculiar situation. It is driving me nuts.

Lisa