Recent inconsistencies on the site

[JohannK]

I suppose I'll post on this version of the site too.  Since last night I've noticed it seems the site is jumping between two versions that seems to have branched on the 20th or the 21st.  The different versions have different certificates, but the same domain name.  The one I'm posting on now also had some (frankly suspicious) behaviour with all links to threads and sub-forums going to a strange IP with a self-signed certificate.  The main site certificate (now used site-wide) was issued on the 21st.

Can somebody perhaps shed some light as to what's going on?

EDIT:  Also, any new posts on one version do not show up on the other.