You have a damaged database is my best guess.
Before we deal with that, a general comment.
If you deselect ‘Copy File...’ then you are telling iPhoto that you are responsible for file management. You need, in this scenario, to move the files from the camera card to whereever you are going to store them and then - and only then - import them into iPhoto.
If you don’t do this then you are not saving your Photos
anywhere.
There are a number of potential pitfalls using a referenced Library.
1. Import and deleting pics are more complex procedures
2. You cannot move or rename the files on your system or iPhoto will lose track of them on systems prior to 10.5 and iPhoto 08. Even with the later versions issues can still arise if you move the referenced files to new volumes or between volumes.
3. Most importantly, migrating to a new disk or computer can be much more complex.
Always allowing for personal preference, I've yet to see a good reason to run iPhoto in referenced mode unless you're using two photo organisers.
Your Library is - apparently - damaged in two way. One, it’s no respecting your choice about not copying to the Library (“ iPhoto has no problems resolving them to a hi-res file within the iPhoto library“ - this would not be possible if the files were not copied and the disk unmounted) and two, it cannot manage your Events. (These may be related to the same problem. It seems that iPhoto is copying +some files+ and not all).
First step:
Download
iPhoto Library Manager and use its rebuild function. This will create a new library based on data in the albumdata.xml file. Not everything will be brought over - no slideshows, books or calendars, for instance - but it should get all your albums and keywords back.
Because this process creates an entirely new library and leaves your old one untouched, it is non-destructive, and if you're not happy with the results you can simply return to your old one.
Regards
TD