Not sure if it’s related to that and it has nothing to do with the URLs of the actual pages – it’s how W3TC handles those URLs internally.
Essentially in one part of the code (retrieving cached pages) they are handled one way. In another part of the code (when you update a page and it invalidates the cached version of that page) they are handled a different way.
The net result is that updating a page doesn’t result in you seeing the updated page on the frontend.
All of this is with memcache. I think it’s fine when you use file-based cacheing as I don’t think that uses cache keys.
