confusion re: photostream, import from memory card, events, etc.

confusion re: photostream, import from memory card, events, etc.

Up until a few weeks ago, my travel-photo-handling went like this:

Each night, I download photos to my iPad for safekeeping. They, of course, wind up in Photostream.

When I return home, I connect my camera card to my iMac (where I have my iPhoto library), and I can "see" the photos on my memory card - the photos which, although in Photostream, I have not yet manually downloaded.

I select and ownload them.

New Events are created in my Library automatically, as I have my preference set to Autosplit Events.

This week, I came home from a trip during which I had downloaded to iPad during my time away.

I connected my memory card to the iMac.

iPhoto did not "see" any photos to import - as far as iPhoto was concerned, those photos were already in my Library.

I had iPhoto show all photos on my card, selected the photos from my trip (I shot over 1000) and clicked "Import Selected"

iPhoto says they're duplicates.

However, the photos have NOT been downloaded manually and there are NO Events in my Library for those days.

Note: yeah, they're in Photostream, but IN THE PAST - and I mean literally up until 3 weeks ago - the photos have ALWAYS been "visible" and importable even if in Photostream, as long as I had not yet manually downloaded to the computer.

So my question, I guess, is multi-part:

What changed in iPhoto and/or Photostream in the past couple of weeks?

Why are Photostream photos suddenly considered to be the same as the photos on my card which have not yet been manually downloaded to the computer?

What the heck is going on?

I hate having duplicates, but I also hate being confused by something that used to be really easy, then - with Photosream - became annoying, and is now simply perplexing and sometimes imcomprehendable.