gpg does not ask for a passphrase anymore

[Giuliano Franchetti]

Hello to all, 


I use gpg for many years and never got a problem. 
Usually I encrypt files and directory with public key system. 

Recently I install duplicity and afterwards I have a strange problem I do not know to solve. 

The problem is that now if I decrypt an encrypted file, gpg decrypts it without asking the passphrase. 
I do not know what happened as before it always asked the passphrase but now not anymore.

Is anybody having a suggestion on how to make gpg to ask the passphrase again? 


Many thanks 


              Giuliano