Using DropBox to sync your Brains is definitely not a recommended practice. A simple file-based sync does not work properly for many reasons. For instance, many large files are modified in small but interdependent ways when the database is changed. Thus, a file-based sync is not only very inefficient, but also prone to corrupting the database. (When for example, the same database file is modified in two different places at once, a file-based sync will have no choice but to ignore one of those changes - likely corrupting the entire database!)
Additionally, there are factors beyond just the visible data that need to be kept in sync, such as index information, internal IDs that are different across machines, and so on.
This is why DropBox and other file-based sync services will work, but cannot be relied on since they tend to lead to corruption as soon as: 1) Changes are made to the data from more than one place at a time or 2) A sync is only partially completed before changes are made at the receiving computer. Worse yet, the database may only become partially corrupted so that you do not find out about the problem until weeks or months later when you cannot easily revert to a backup.
We recommend backing up your Brain on WebBrain.com. If WebBrain is not an option for you, a .brainzip backup is the next best thing. .BrainZip backups, however, need to be created manually.
In your initial screenshot, it looks as though this is an issue that was similar to one recently resolved in our latest release of TheBrain 220.127.116.11, available HERE