Ah, I see the problem now. Goodreads recycle their user ID numbers between authors and users. The WordPress.com widget shows *users*, which user number 6038587 belongs to the lady whose books you were seeing.
On the other hand, an author, like yourself, has a different set of IDs, which apparently, do overlap.
For the record, your GoodReads user number is 15245776. I was able to find that by going to your Goodreads author page, then clicking the tiny "RSS" link on the right of the "Ronald's Recent Updates" section header and noting the number in the URL.
I've placed the WordPress.com widget in the sidebar of my test site using the 15245776 number here: http://kraftsandbox.wordpress.com/
Thanks for your patience as we together discovered this unique aspect of Goodreads!