Apahce SSL Cert Centos Issue

I'm looking for someone to help check over my SSL certificate install in apache. Some computers that visit the ssl version of my site get an untrusted certificate error and some computers that visit the site get the proper certificate. I'm not sure why some people get the correct cert and some get the self signed one. I moved the cert from another server weeks ago so shouldn't be a propagation issues. The computers I'm testing connecting to ssl are also all on the same network. Thanks,