I was trying to install a new login screen theme through the system settings window, but nothing I downloaded would appear in the theme tab. I've been trying to find information on where I could find the default location for login themes, but have not had any luck so far. Any assistance would be greatly appreciated. I'm not sure what kind of information would be helpful in this situation, but I've included my version information below. Please let me know if there is any other information I can provide.
DESCRIPTION="Linux Mint 12 KDE"