Importing photos again after deleting in iphoto

Hi, today I tried to import photos from an iPhone to iPhoto.

As soon as I connected the phone and trusted the computer, Dropbox kicked in and started pulling the photos already.

Since this was not what I wanted I killed the proces and turned of the feature in Dropbox.

When I opened iPhoto It seemed part of the photos were there already. So I deleted them to do a clean import again.

After deleting the pictures from both my "camera uploads"-folder in dropbox and my iPhoto library, I hooked up the iPhone again.

This time only the photo's not yet imported are shown in the import window in iPhoto.

All the other photo's still remain on the iPhone but are not seen by iPhoto.

I tried Image Capture as well, with the same result.

I even tried it on a different macbook, but still only the not yet imported pictures can be imported.

The pictures are definitely still on the iPhone, but just not recognised by iPhoto, Image Capture or even Photos.

I tried resetting netwerk setting and privacy settings in the phone, but to no avail.

My personal idea is that somehow inside the phone the pictures are marked as "imported" and therefore not shown to this software anymore....

Any ideas how I can still import ALL pictures regardless if they have been imported before or not?

Hope you guys can help!