Yes, in my experience, using dropbox, you end up with two versions of the keypass file (one listed as a conflict). I've been using this setup for ~10 yrs, and it has only happened 2 or 3 times, but as I'm the primary user, I would expect this to happen more often with a family sharing the same file. If things are working correctly, the keepass lock file created when opening a db is synced via dropbox, so any second attempt at opening the file on another system results in a warning to open it as readonly.