Force an update on sitemap?

I've got a website I'm using wpmu dev seo on. It's in a subsite in an MU installation and i've completely deleted a post..

It's been almost a month and that post is still in the sitemap. I've emptied it from the trash as well.

In general the website sitemaps seem to be updating just fine.. Is there a way to manually edit a subsite's sitemap so I can fix this? Because it doesn't seem to be updating..

You guys should really add a "force update" button..