Troubles with mod_ssl ssl.conf configuration on one domain

Hello all,
I am having a slight problem with ssl. My system specs are: RHEL 3.1 running Apache 2.0.x
I have everything set up in a separate ssl.conf file and include that file from my httpd.conf file. When i do an 'apachectl startssl' it prompts me for the passphrase and everything is good. however, i am having a problem with my ssl virtual host. right now i have it set like this:
...
...
<VirtualHost _default_:443>
# General setup for the virtual host
DocumentRoot "/home/online/public_html"
ServerName www.mydomain.com
ServerAdmin webmaster@mydomain.com
ErrorLog /var/log/sec_httpd-error.log
TransferLog /var/log/sec_httpd-access_log
SSLEngine on
SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL
SSLCertificateFile /usr/local/apache/conf/ssl.crt/server.crt
SSLCertificateKeyFile /usr/local/apache/conf/ssl.key/server.key
...
...
...

now, when i do this nothing happens when i startssl. when i type in https://mydomain.com it just comes back 'page cannot be displayed'
i can, however, go to mydomain.com:443 with no problems
when i change _default_:443 to mydomain.com:443 in the ssl virtual host, then the site can only be reached through https
eg.
"Bad Request

Your browser sent a request that this server could not understand.
Reason: You're speaking plain HTTP to an SSL-enabled server port.
Instead use the HTTPS scheme to access this URL, please.

Hint: https://www.mydomain.com/"

can anyone lead me into the right direction as to how i can have my site both on the https AND http protocol?

any help would be greatly appreciated!
Thanks!
-Joe