CB with Panels 3

Yes, what have you tried to do? What kind of panel are you working with? What do you want the breadcrumb to be and what are you getting?

If its a panel node, then you create the custom breadcrumb for it just as you would for any other node type. You don't even need to enable the custom breadcrumbs for Panels module. But for a custom panels pages, you'll need to enable this module. After doing that, you can add a custom breadcrumb for a custom panels page at admin/build/custom_breadcrumbs. Just click on 'panels' , select the custom panel page from the select box, and add the custom breadcrumb titles and paths as usual. That's the basic idea. It may vary depending on what you are trying to accomplish, so providing details will help.