I think it would be very helpful if the default listing of items added to the dropbox (appearing under in the Dropbox tab and in the Files section of Add an Item) were listed by default alphabetically. This would make it much easier to select and cluster a group of files as a single item. Conversely, I can't think of what would be lost by having these files appear in a list sorted by name.
[updated] Argh, you can filter files dynamically by name in both places. Why didn't I notice this? This in effect allows me to select and cluster files and it's even faster than manual selection from an alphabetized list. An alphabetically sorted list would still be useful (since as far as I can see the current order provides no value) but it's no longer pressing.
[Update 2] However, an alphabetically sorted list would still be very useful since the filtered list is returned unsorted. As a result, adding multiple files at once creates an item whose files are in the wrong order.
Specifically, if I place a sorted list of files in the dropbox, e.g.
Zirkus des Lebens-Program_Page_01.png
Zirkus des Lebens-Program_Page_02.png
Zirkus des Lebens-Program_Page_03.png
I'd like these to be added to the item in this order. Not sure if this is now a bug or a feature request.
So, did you click on all 3 the files from the Add item ->Files tab at the same time and then Add Item or Save Changes?
Have you tried associating the files with the item, one at a time. Select Page_01.png from files tab, save changes; select Page_02.png from files, save changes?
In Add New Item > Files, I filtered for the name from the list in the dropbox, selected all the filtered results, and then saved the page.
Selecting and adding them one at a time works, but I have lots and lots of these multi-file items...
As a parenthesis, this actually caused Omeka to crash after five items were imported, but I think that's an unrelated issue. I've posted the trace in the Troubleshooting forum.
To be more precise, I filtered for the name from the list in the dropbox, selected all the filtered results, and then saved the page. This caused a crash. I then created a test item, gave it a name and saved it and then went to Files and added the files as above and saved. Also a crash. At this point I think I probably have a corrupted database (due to missing/partially created files from previous attempts to upload multi-page TIFFs and PDFs) so I've nuked my Omeka install and will start again.
This crash was caused by trying to add an item (it didn't actually matter that it was several) to an existing item for which derivative images could not be created by Omeka (multipage PDF). The bug is described in more detail elsewhere on the forum and so I'm closing out this topic. It appears to be addressed by this patch.