We had the same problem here after the upgrade to 10.7.4. Here's what resolved the issue:
- Logged-in as root user
- Applications->Utilities->Keychain Access->Preferences
- Reset Default Keychain
I actually ran into one problem with this, "Reset" failed with an "Could not obtain authorization for this opperation" error and left me w/o a login keychain (If you encounter this, please report this bug also); however, running "Keychain First Aid" fixed that.