Disappearing documents

This must be the stupidest question ever, but what am I doing wrong? I’m working in D3 to try to cut duplicates and file the absurd 140,000-plus documents that DevonAgent Pro dumped on my database. I’ll be merrily working in the INBOX and suddenly all of my documents will disappear. No clicking anywhere–Inboxes, Trash, Recently Added–retrieves them. Poof, all gone. When I quit D3 and re-open they reappear, only to vanish again.

t’s maddening and has me thinking I’m too dumb for this wonderful program and need to find a new one. What am I doing wrong?

Hold the Option key, and choose Help > Report Bug to start a support ticket. Please include a screencast of the behavior. Thanks!