Missing widgets?

I just upgraded to WordPress 2.7. I’m using the CVS version of Thematic, downloaded about twenty minutes ago.

It reset the widgets that are displayed, which tells me the is_sidebar_active function might not be working.

When I go into the widgets configuration in the admin panel, the widgets I had installed in various sidebars and such are not shown. They’re marked “in use,” but when I show the panels where they’re supposed to be, nothing is listed. I can add new widgets to these panels and those ones work as they should.

How do I reset the widget assignments?

I realize this might be partly a Thematic problem, but I figure the widget assignments themselves can be reset to fix it.