I'm trying to remove items from a collection. They won't delete. I've tried right-clicking and selecting "Move item to the trash" and hitting the delete button - in both instances a little pop-up appears asking me to confirm. I click yes ... aaand, nothing happens. The item is still there. Sometimes it appears to delete, only to magically reappear later. Sometimes, another unselected item disappears instead. It's a great mystery, and it's wreaking havoc with my attempts to wrangle 150-odd sources for a literature review. Any thoughts? I'm doing in the app, not the web-app, and I only downloaded it yesterday.