Yup, I've read the readme, read through the issues queue, etc etc. Not my first time to the rodeo!

Okay, I've got three apps being hosted by a client site. The first two work great, and were created pre-October 2011. They are extremely simple apps: all they do is display content from the site, as a tab, on a client's page. Easiest thing in the world. I've gotten it to work twice.

I'm trying to create a third tab (and I'll probably be deleting the first two when I get it working). Exactly the same scheme in every way: I've got a single page of content that I want to display as a tab. I'll be setting the tab up as a "landing page" for non-fans on FB.

When I go to the app's canvas page, rather than loading the assigned Page Tab URL (as designated @ FB), the canvas page trigger's my site's search function (via fuzzysearch module's "let me search 404 results"). This tells me that FB isn't actually asking for the Page Tab URL, but rather something else entirely and that is firing off the 404.

When I turn off the fuzzysearch 404 handling, the canvas just takes me to my homepage. Which is basic Drupal handling of 404 codes as I understand it. It does give me a "page not found" entry in the Drupal log, and gives me the URL that it couldn't find. When I manually copy and paste this URL, the page comes up just fine. So I have no idea why the app (apparently) can't find the page.

Global Redirect is not enabled.

I've compared a working app to the non-working app side-by-side on both the FB and Drupal side. They are identical in every way. One works, one can't find the page. The only places they cannot be identical is in the advanced settings on FB, which are now different since the October 2011 changeover to Opengraph.

Any ideas?