Breadcrumb trail not being generated for shared content

Hi there,

I have a primary domain, and 2 other domains. Each domain has it's own primary menu, which are working fine, even if I share a page across domains. However, I'm noticing that if I share a page on multiple domains, and add the page to each domain's primary menu, then something strange happens to the breadcrumbs. Let me see if I can explain how to reproduce it:

1. Create a page on the primary domain, and add it to that domain's primary menu, say under "About Us" and the page is called "History" - so Home -> About Us -> History. The breadcrumb should say: Home -> About Us, and it does just fine on the primary domain.
2. Assign the page to a secondary domain.
3. Go over to the secondary domain and visit the page, which has no menu entry here yet. Then go up to Structure -> Menus and add this item to the secondary domain's primary menu. Save it off.
4. Viola! The breadcrumb is there on the secondary domain: Home -> About Us
5. Refresh the page - breadcrumb now just says "Home" - but a menu block still shows the page in the About Us section.
6. Blow out the menu cache, breadcrumb is back to "Home -> About Us"!
7. Refresh the page - and it's gone again. In the meantime, the primary domain's breadcrumb for this page is a-ok.

I'm not sure if this is a bug or a user error on my part, but I can't seem to figure it out, cheers.