The first time I tried ghosts they all died overnight (January 2012). Granted, in hindsight I did add them to a brand new tank after acclimation, one was harmed by the employee while getting caught so he died first and the other 2 followed. The spike in ammonia put my betta Lakitu in shock, and he died a week later. I was devastated.
So, this January (2013) I bought red cherry shrimp off a hobbyist, rather than a store, and gave them their own tank. They have since thrived and I have week old babies and another mama carrying eggs. They're so bright and fun. :)