If I understand you correctly, I've had same problem. Found I can still access vault entrees through "Search Your Vault" function after tapping LastPass icon on Firefox menu bar, or using various tabs under that, such as "All Items," "Favorites," and "Recent." For some situations, it's actually easier than scrolling through entire vault listings to find what you want, which is not to say I don't want the problem to go away.
You have understood the problem correctly, they are accesisble through the Addon.
Contrary to you, I found the site much easier, and wondering why a simple web page doesn't work...
