WordPress version: 3.5.1
WordPress SEO version: 1.4.7
I did this: Updated the plugin to latest version.
I expected the plugin to do this: Not change anything.
Instead it did this: Returned a 404 (page not found error) when clicking any product in my Shopp ecommerce plugin store.
I deactivated WordPress SEO, Hey Presto! all my products re-appeared!
Then reactivated WordPress SEO - now all good.
Exactly the same thing happened with both our live site, and our duplicate test site - after updating this plugin.
Deactivating, then reactivating the plugin fixed the problem both times.
I do have W3TC activated on our live site, but this is not a cache issue because the same behaviour presented on our test site (where W3TC is not activated).
Really weird behaviour: all our products were off air for a full 2 days before I realized.
Don't know if its related; but around the same time Google started displaying our meta title incorrectly in search results (It is all jumbled with the last half displayed first).
It is displayed correctly when you access the site in a browser.
Because our site has now got dumped a full page back in the organic search results, I have submitted a reconsideration to Google.