apache - ssl virtual host issue on EC2 LAMP

Question

I am having issues with SSL and virtual hosts on my EC2 LAMP instance
My virtual host prevents service httpd start to work, im getting [FAILED] without any clues as to why.
I have a ssl.conf present in my conf.d folder.

I dont seem to see any error logs inside /var/log/httpd
Also ssl_engine.log is empty

<VirtualHost *:443>
        ServerName app.mydomain.com
        DocumentRoot /var/www/app.mydomain.com
        SSLEngine on
        SSLCertificateFile /etc/ssl/certs/certificate.crt
        SSLCertificateKeyFile /etc/ssl/certs/app_mydomain_com.key
        SSLCACertificateFile /etc/ssl/certs/mydomain.ca.crt
        ErrorLog /var/log/ssl_engine.log
</VirtualHost>

are there any test i can perform to better understand where the error might be coming from?

Im finding out that when i get rid of ssl.conf and any virtual domain with <VirtualHost *:443> apache will start, other wise nothing happens and i cant seem to find any error logs.

update: i took this out of ssl.conf and apache will now start.
working backwards to see how this is creating an error

<VirtualHost _default_:443>
    ErrorLog logs/ssl_error_log
    TransferLog logs/ssl_access_log
    LogLevel warn
    SSLEngine on
    SSLProtocol all -SSLv2
    SSLCipherSuite ALL:!ADH:!EXPORT:!SSLv2:RC4+RSA:+HIGH:+MEDIUM:+LOW

    <Files ~ "\.(cgi|shtml|phtml|php3?)$">
            SSLOptions +StdEnvVars
    </Files>
    <Directory "/var/www/cgi-bin">
            SSLOptions +StdEnvVars
    </Directory>
    SetEnvIf User-Agent ".*MSIE.*" \
                     nokeepalive ssl-unclean-shutdown \
                     downgrade-1.0 force-response-1.0

    CustomLog logs/ssl_request_log \
                        "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
</VirtualHost>                                  

finally got an error
SSL Library Error: 185073780 error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch