We're able to replicate this on both a local 3.0.2 install with a child theme of Thematic, and a remote install of 3.1-beta1-16642 with a child theme of Thematic - in our case, we can't get the thematic_sidebar(); to display on an archive-CPT.php page, but sidebars and widget areas work fine on single-CPT.php pages. Source view shows:
</div><!-- #content -->
</div><!-- #container -->
</div><!-- #main -->
where the sidebar should be showing up between the ending container and main divs. No errors display in the error logs, the function thematic_primary_aside does not get called on the archive-CPT.php page.
If we use the index.php file to render the page (default), the sidebar, etc. works. But when we try to re-route it to use a archive-CPT.php page as the template, the sidebar and widgets don't display.
We're using a template redirect to an archive-CPT.php page inside the child theme. When it's being used, the widgets are not displaying - so maybe when you redirect to a Custom Template, the widgets don't get registered - so what do we do to register them?
Putting the dynamic sidebar function in directly makes it display. And using the default TwentyTen theme everything is fine and displays correctly - so maybe it's either a child-theme issue, or a Thematic issue???
(Sorry, I'm explaining this 3rd-party, so I might be mangling the description of what's happening a bit).
SO - does anyone have a clue as to what we need to change/add to get the functions for the sidebar/widget areas called?