Cannot open my website. Getting SSL_ERROR_NO_CYPHER_OVERLAP error after activating Cloudflare

Hi! Have been working with Cloudflare for a while now. Suddenly today we get the error:

Secure Connection Failed

An error occurred during a connection to Cannot communicate securely with peer: no common encryption algorithm(s). Error code: SSL_ERROR_NO_CYPHER_OVERLAP

Here’s the strange bit. This only happens on Comcast ISP customers. I have been on chats all day with bluehost and Comcast and they both tell me that I need a SSL 3.0 certificate. Apparently comodo is the reputable SSL 3.0 provider, and both recommend them. I get on a chat with their tech guy, and he tells me he can’t trace any SSL certificate at all.

This is a HUGE mess… anyone have ANY thoughts?