Apple today released Safari 4.0.3 via Software Update and direct download. Not ones to be caught sleeping on the job, our crack team of ninja developers have countered with 1Password 2.9.23, an update that makes it compatible with the new version of Safari.
You can nab the 1Password 2.9.23 (or newer) update with the "Check for Updates..." option, found under 1Password's application menu.