The blog just said:
You were pinged back by
https://mihail.stoynov.com/blog/2009/05/10/TestBlogPostWithWindowsLiveWriter.aspx
on your weblog entry 'Usability of the blog'
(https://mihail.stoynov.com/blog/2009/05/05/UsabilityOfTheBlog.aspx
I’ve linked myself in the past but I guess this feature was off or broken.