Trackback auto-discovery is not sending trackbacks

I have a customer wich I provide webhosting for that is using Atahualpa.3.2, and have a support ticket from her about trackback auto-discovery wich isn't working.

Manually sending trackbacks by copying the trackback URL from other WordPress blogs and pasting into the field for trackbacks in her blog posts is working, but not the trackback auto-discovery: When she link to another WordPress blog, the trackback shows up as being sent in her blog post in the admin area, but it is not really sent, and will never arrive at the other blogs.

Also internal trackback auto-discovery is not working for her, wich have the same problem that it isn't actually being sent, and will never show up.

On the same hosting account, she have another WordPress blog with a different theme, and trackback auto-discovery seems to work on that blog, and is sending trackbacks with no problems – that is why I think it is a problem with the Atahualpa theme.

Can you confirm that this is a issue in Atahualpa 3.2? And is it fixed in Atahualpa 3.3.3? If not, what can I do to fix the issue?

Thanks!

Edit: She is using WordPress version 2.8