Upgrading 1Password Causes Slowdowns or Freezes
When using the OS X Keychain, sometimes following an upgrade of 1Password your computer may slow down considerably and/or freeze when a program accesses the keychain. This is a known issue in the OS X keychain and has been reported to Apple for resolution.
This issue is quite common and can happen in many situations, as documented by this Macworld article. The Macworld article points out the problem is caused by a corrupt file used by Mac OS X. Deleting this file forces Mac OS X to rebuild the file and thereby resolving the problem.
You can fix this issue by using Finder to drag this file to the Trash:
/var/db/CodeEquivalenceDatabase
The /var/db folder is hidden by default in Finder, so type cmd-shift-G (⌘⇧G) to open the Go window. Then, type /var/db and click the Go button. Once there, drag the CodeEquivalenceDatabase file to the Trash, and enter your administrator password if Finder requests it. After deleting this file, restart your Mac and the problem should be fixed.
Once this issue has been resolved, it is highly recommended that you upgrade to the Agile Keychain format to prevent this issue from happening in the future.