A PHP/MySQL application we've built uses LDAP for user authentication. Now the powers that be wants this to be used over HTTPS, but when the tests we've done don't authenticate properly against the LDAP server.

Here's the .htaccess file we're using (and which works beautifully over HTTP):

AuthType Basic
AuthName "App Authentication"
AuthLDAPEnabled on
AuthLDAPAuthoritative on
AuthLDAPURL ldap://ldap.ourcompany.com/dc=dc1, dc=dc2, dc=dc3?uid
Require valid-user
But when I do a simple thing like

PHP Code:
on the HTTPS connection I get nothing. No login box comes up, only the usual certificate information and then nothing. If I do the same thing over HTTP, it works fine.

So where's the problem? Web server configuration, LDAP server configuration, .htaccess file or just a bone-headed developer?