Lightroom Question - Importing a Catalog

[doodah]

Probably a newb question but I just upgraded my HD and had a fresh install of W10. When I imported my catalog, all of my edited photos from the previous catalog have imported into one go without been in their separate folders. And even if I select the a specific set of photos to develop, it simply shows all ~2000 photos on the reel in develop mode. Have I missed something?

Also, does this mean I have been importing new photos to edit incorrectly? I simply click add new folder on the left pane, select the ones I want and move over to the develop tab.

 

[doodah]

I can restore the old catalog absolutely fine, it's just that none of the pictures seem to remember their folder structure so they all import in one go, all of them along the one reel.

Edit - I don't mind starting a new one and manually importing the same folders again (~40), however I assume all of the edits I made won't be there.