How to fix vault mismatch on dropbox [moved to email]

I've been using the latest versions of 1 password on an iPhone 5, iPad3 and many different Macs with no problem. I sync exclusively through dropbox, and to the best of my knowledge, I've never set up any other vaults etc. When I went to pay a bill via online banking today from my iPad, I discovered that 1 Password on the iPad was using the wrong log in info. When I chose the sync prefs on the iPad and pointed it to my dropbox keychain, I get a warning about a vault mismatch on the iPad. Hitting more info tells me that my iPad has 410 items and was last updated two days ago, while my dropbox vault has 392 items and was last updated one day ago. I also noted that the password hints for each vault are slightly different.

How do I fix this problem, and how did it happen in the first place? To the best of my knowledge, I've never used iCloud to sync 1Password. My iPhone and Macs seem to be syncing fine and have no problems. I really don't want to venture into "sync anyway" territory without knowing how much damage it could do across all of my devices. Lastly, it would be much much much more helpful if the "more info" button on the error message would tell me what the iPad synced with exactly to narrow down the problem.