Cannot decrypt Connection String after encryption

[sirnose1]

I used the command line tool to encrypt a connection string using the command:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -pef "connectionStrings" C:\inetpub\CIUI_Test_09052013 -prov "RsaProtectedConfigurationProvider"

This worked fine. However on decryption I used:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -pdf
"connectionStrings" -app "C:\inetpub\CIUI_Test_09052013"

Using -pd instead of -pdf didn't help. The encryption/decryption is all done on the server. Why is my decryption failing? Thanks in advance.