Previous Posts points to only custom post types

I’ve been playing around with the Whiteboard framework and trying to integrate custom post types into the theme. Basically I have one loop that calls recent blog posts in the sidebar on the front page and one loop that calls a custom post type (twb_lessonplan) in the content area: Test Blog here (There’s also a featured content loop but that just calls one post). The lesson plans also display kind of funky.

Ideally I would like to have separate previous post links for both (blog posts and lessonplan posts). Both would lead to a more normal looking blog page (which I have pulled off with a different template file and a conditional tag). At the moment users who click previous post link under “blog posts” see page 2 of only blog posts, which is what I want.

However click on the older post links under lesson plans also displays page 2 of the blog posts. I would like to display only lesson plans i.e. page 2 will continue the same query from the homepage.

Any ideas or even suggestions of where to look would be greatly appreciated.