I select an encrypted email in gmail.
It displays the encrypted data on the screen.
A dialog pops up asking for the passphrase.
I enter it.
The encrypted data goes away and is replaced by a white area
along with two locks along the left side.
No decrypted data appears.
Along the bottom another lock appears with a green dot and the words 'decrypted email'.
This email displays properly in mutt.
ubuntu 9.04, firefox 3.0