Today I've had some serious problems trying to add scans.
Since Firefox doesn't support Flash anymore I had to use to "I can't use Flash or Javascript" way. When I added a file for all 5 boxes and pressed "Add Covers" I'd always get an error message about something like "File size too big" but none of the files were bigger than 5MB. After that I had to delete the cookies since I couldn't remove the chosen files from the boxes anymore.
Uploading a scan one at a time worked for me again. But then again, when I choose "Booklet" and added "p. 01-02" manually, it resulted in "Booklet pg. p. 01-02".
After that I tried Bing where I still can use Flash but after uploading a few files and refreshing the page not only was I suddenly logged out but also all captions were deleted. See
here.
Didn't try Chrome.
I hope the upload system is gonna be revamped at some point.