Can you tell me what browser/etc you are using? I replaced the cert a month ago on expiry and believe it is serving the correct one, and have verified this independently as of a minute ago, so I am wondering if there isn't a caching issue somewhere.
It was Google Chrome (36.0.1985.125 build 283153).
I've checked again today, and now I don't get a SSL warning. I am pretty sure I've never visited your site before, so I don't think it's caching on my end.