Custom Domain on Developer Portal not using a valid certificate

I've configured a custom domain to my portal, but when I access the portal, it is still using the *.apigee.net certificate instead of the one I've choose. What should I do?

I'm also trying to create a custom domain for my APIs, but when I try to create a Virtual Host, I got the following message:

"Virtual host creation/update failed due to keystore cert validation error. Cert is invalid or cannot be not be trusted by java trust anchors or CAs"

Any help?