Highend and https

Hello,

I’m converting a wordpress site with highend to https (hosted on AWS EC2). I get good results (ie secure appears next to the lock) when highend is not activated but when I activate highend, I have 3 problems –>
1. on a mac, the logo (main header) on the page is replaced by a question mark but the padlock is visible
1. on windows with explorer, the logo (main header) on the page is replaced by a question mark but the padlock is visible
2. on windows with chrome, the secure disappears and it is replaced by ! but the logo is visible (main header).

I’m using the plugin SSL Unsecure Content.

Do you have any idea what could be causing it?