Nested Comments Stopped Working in Atahualpa 3.7.3 with WP 3.3.1

Hello,

I have run into a bit of trouble five days prior to a big event that I am hosting on my website.

I have always used nested comments (up to 10 deep, for better or worse), but today a user reported that comment nesting was not working. Oddly, it is working for MY comments as admin, but it is not working for comments by other users.

You can see the behavior here: http://www.thinkkidthink.com/eds-top...-2012-poems-5/ (The comment by "Charles Mund" was me while logged out and I am certain that I replied directly to another comment using the "Say Something To This Person" link.)

You can also see that it has worked fine in the past here: http://www.thinkkidthink.com/10-rewind-vs-15-derelict/

The only thing I've changed recently is adding the Subscribe to Comments Reloaded plugin, which I just disabled to test, and the issue was still present. (I have since re-enabled.)

Any ideas what could be causing this misbehavior?

Thank you in advance for any help that you can provide.

Regards,

-Ed