Safari incorrectly demands to select an SSL client certificate
We were having this problem on our site with Safari users on a mac/macbook (iOS was okay).

On our server (Apache) we commented out two optional parameters in the httpd 'conf' file: SSLVerifyClient and SSLVerifyDepth. Our SSLVerifyClient was set to 'optional' which seems to be the issue. The default is "none" and I believe not commenting out the SSLVerifyDepth creates problems as well.