Most of the "tricks" are described either here: http://cintanotes.com/cintanotes.htm or here: http://cintanotes.com/forum/viewtopic.php?f=3&t=156

Sorry to hear about the computer, I know how painful it is to reinstall everything. Good luck to you with that.
About the settings file: please also make sure that the filename (cintanotes.db) is included in the notebook.file param (like "notebook.file = c:\my dropbox\cintanotes\cintanotes.db").

Added as a separate idea: http://roadmap.cintanotes.com/feedback/10418-note-version-history/

Indeed, there should be just one cintanotes.db inside of DropBox folder (but the DropBox folder may be in different places on different PCs). And no, you don't have to re-install DropBox. But you have to edit each cintanotes.settings file to point to that PC's cintanotes.db. Please tell me what "notebook.file" param value is on both your PCs? Thx