dj_paige wrote:
What it DOES do is give me a way to re-import the images and get all the changes I've made back...
Thanks for pointing this out, I must have misunderstood.
If changes have been written out to the files, and then (for whatever reason) the changes in the Catalog have not worked out in some way - lost (though I have never encountered that), you want to undo a large-scale accidental change done since, whatever... it is not necessary to re-import. You can "read metadata from file".
(This only works where the Catalog concerned has not written changes out automatically, subsequent to and over the top of earlier external metadata that you would like to load back in).
However I would agree that checking the specific Catalog used now vs previously, is a good idea. It is not usual to need to browse to and open a Catalog when starting LR, unless the one last used, is for some reason not available where last found. So something odd may be going on. New Catalogs are generated when you go from LR3 to LR4 - could that be it?