Very weird...
Would you mind reinstalling the app -- to make it easier please use Menu -> Backup & Restore on the app's main window, before uninstalling (Backup) and after reinstalling (Restore)?
If the issue persists, I'll need to get a debug log please -- capturing:
- the app receiving messages (even if they don't show)
- your opening the message list (empty)
- doing "compact the db"
- and finally reopening the message list (now with your messages)
Then I should be able to track it down. Thanks.