I have multiple accounts configured. They all have the setting "Always encrypt when replying to an encrypted mail" enabled. But if I reply to encrypted message, and change from one account to another, the reply messages Encrypt setting is lost. Further, even if I switch back to the account that received the message, the Encrypt setting stays lost. I consider this to be an important security issue.
That's because it takes the options from the newly selected account. That option is only applied at the point you hit Reply.