I know I've read about this somewhere in the threads and it looked like you knew of the issue. Seems that after installing 0.1.8 the publishing of a post becomes a lot slower.
Wierd is that it gets hung up somehwere in the queries. The post is being published in the backend, but the admin is left with a "in progress" page which usually takes up to 2 minutes to refresh and show the "published" message.
PS: even so, it is the best SEO plugin I've worked with
PS 2: I like the auto-generation of titles better (it recognized the format introduced in the Titles page, which isn't happening anymore).
PS 3: best thing: focus keyword.