Update: 1Password has released version 2.5.12 which supports Safari 3.1. Open your 1Password program and check for updates to install.
Apple today updated Safari to version 3.1, which breaks 1Password. I'm sure the makers of 1Password will be releasing an update in the next few days to address this, but in the meantime the steps below will get everything working again. You do not need to worry about undoing this when the 1Password update is released.
- Close Safari and 1Password
- Open the file /Applications/1Password.app/Contents/Resources/SupportedBrowsers.plist in a text editor
- For the key Safari, change the MaxBundleVersion to 5525.13
- Open 1Password program, go into Preferences, Browsers tab, make sure Safari is checked as installed. If not, check the box.
- Open Safari and you should see the 1Password icon on the toolbar.
Be careful doing this in the future. If Apple were to make major changes to Safari, then this technique could do more harm than good, but I have verified it works with Safari 3.1