I have been using 1Password for a year or so on OS X and just bought the license for Windows as well, which I am running via Parallels on my Mac. I managed to sync the data using DropBox so that it automatically worked the first time I started 1Password in Windows.
On the Mac I have 1Password set to backup the keychain data once a day and keep 50 copies. Now looking inside the Windows version it has the same setting, backing up to the same folder that is stored in the Mac part. Is there any risk of duplicating information or creating problems here? If I disable it on the Windows side will that automatically disable the Mac side as well via dropbox? I'm hoping you guys have thought of this so there are no conflicts, especially if both systems are running at the same time.
With all the keychain data now being stored in the DropBox folder isn't there a greater risk of file corruption with all the uploading and downloading of data?
For all the other points like saving & sharing login details across different platforms I'm assuming we are safe and that login data stored in one OS will automatically be available in the other OS. I think Agile have said before that using DropBox is safe for storing and transmitting our keychain data.