Hi Rui,
Thanks for your feedback.
Since it was only the logo which was causing the issue I decided to fix the problem myself. In the sf-header.php file there is this code:
// Standard Logo
if ( isset( $sf_options['logo_upload'] ) ) {
$logo = $sf_options['logo_upload'];
}
I simply added an extra line of code to check for ssl, so it looks like:
// Standard Logo
if ( isset( $sf_options['logo_upload'] ) ) {
$logo = $sf_options['logo_upload'];
if (is_ssl()) { $logo = str_replace( 'http:', 'https:', $logo ); }
}
And now it works perfectly. The checkout and account pages use SSL without problems.