Correccion Falsa Alarma
This alert was caused because the iphone date was changed (as pangu required) therefore the google served could not autenticate the user.
It was just a mater of getting it back to normal.
BUT never forget that any jailbreak means a security compromise.
After Jailbreak your passwords (at least gmail) will be compromised.
I use my google calendar through my iPhone and after Jailbreak the following message appeared:
“.....@gmail.com can´t verify the identity of `www.google.com´...” and other similar one “.... the identity of ´m.google.com´...”
I understand that it is because is trying to get access to google.com through a proxy or a “man in the middle” and in case you continue all your passwords can be copied.
You can see a screen capture here.