Keychain/Keychain application is located in Macintosh HD > Applications > Utilities > Keychain/keyring.
Often, some applications we continually ask the password for the keyring. This is linked to this application. Therefore when repair Keychain/Keychain for this problem stop.
-- Fix Keychain/Keychain
Open application and go to the Window menu and select "Keychain First Aid/Repair Keychain", save the user password and select "Repair/repair".
-- Change the user password for the password user agrees
Sometimes Keychain/Keychain fair because the user has had problems with user password (login) fairly recently, in these cases, the solution is to resynchronize the password by going to change the user password in System Preferences.
-- If problems persist, it may be that things are more screwed up than in this case, go to your "Home", "Library / Library '(Macintosh HD> Users/Users> Home > Library/Library > Keychain) and in this case, put on the desktop the file is called "login.keychain.
Warning: this name may vary depending on the version of OS X you have. Caution, this implies the loss of passwords for everything (except login because it is store elsewhere).
This should more than solve problems related to this application.