I am curious about this too. Except I currently have a Dreamweaver site that is edited by some of my coworkers with Contribute. We are thinking about converting our site to Wordpress to gain some of the functionality and widgets that are part of WP world. But I don't want to make the switch if it will "break" our ability to use Contribute to edit the pages as we are now. Some are basic pages and need only editing once every few months. Some pages are taken down for parts of the year and "inactive" for a time. I want to know if we will be able to use Contribute once we convert our site to WP if we do decide to do so.
I have seen a similar problem today.
We have our blogs hosted at wordpress.com. In Contribute 6.5 (never before having touched the blogs in it) I went to add my blogs, entered my wordpress login details. Contribute spent a bit of time loading stuff. Then I had to go to lunch and shut Contribute down without editing anything.
When I got back I was informed by my colleagues that all of out blogs (which they had subscribed to be email) had sent them emails that were essentially empty. At the time I assumed that they got them because they are also blog admins.
On our test blog (which is hidden) I did a test post. It posted OK but when I tried to edit both an existing post and the post I had just done Contribute responded that I did not have a connection to that site. I noticed that the domain had changed from http:// to https:// - I've looked for a way to tell Contribute to see these as the same but can't find any.
Then we got feedback from a customer that he'd got the emails as well. So it appears that ANY activity by Contribute is triggering wordpress to send these updates. And from what I'm seeing now it does it whenever I connect with ANY of the blogs.