I'm using 1Password 4 on our iPhones, and 1Password 3 (MAS version) on our desktops.
I added a text field in a Bank Account entry for an additional PIN (we each have separate cards associated with the account). This field synced over fine to my wife's phone, but did not to the desktops. All are syncing via Dropbox, and the Agilekeychain is located in a 1Password folder inside the Dropbox folder.
My MacBook Pro is running 10.8.5, and her iMac is running Lion 10.7.5. (It's one of those that can't go to Mountain Lion…)