Can I export from 1Password v5 to v3 in order to keep 2 separate libraries in sync?

@WallyW: I think that syncing your data would be both easier and less confusing, with one significant caveat (which I believe is also related to the issue you're describing): 1Password 3 knows nothing of the new formatting in 1Password 5.

1Password 5 (also 4) supports custom sections and fields in addition to the preset "templates", and once you edit an item on a newer version, you'll find that going back to the old can result in "missing" data. Fortunately, it's all there, and we've made sure that this doesn't break anything; but this also means that switching between the two and making edits on both has significant drawbacks.

The simplest way to put it is that if you edit an item in 1Password 5 (which creates the new sections needed for customization), you can still read all of the non-custom data in 1Password 3; but if you then edit an item in 1Password 3, it is only writing to the "legacy" section; so when you go back to 1Password 5, those edits will not show up, as they are ignored in favour of the new sections (which 1Password 5 created the first time you edited there, but 1Password 3 does not use).

So I'd recommend using Dropbox Sync to keep things up to date between yourself and your wife, but make sure she does not edit with the old version of 1Password. She'll still have access to the most important parts of the data (username, password, URL, and all the "standard" bits), just not the custom stuff (which you may or may not even use).

Granted, a better long-term solution would be to upgrade your wife's Mac, but obviously this isn't always an option. I hope this helps. Be sure to let me know if you have any questions! :)

Any time! You're most welcome! Be sure to let us know if you have any other questions. We're always here to help! :)