For some reason I'm not connecting to WordPress functions via Jetpack or RSS.
Specifically, Site Stats, my Twitter Connection and two WordPress-based RSS feeds are not functioning.
I've checked that the stats are working via the WordPress Stats page and Akismet seems to be working fine, except I'm getting loads of spam. Other non-Wordpress-based RSS feeds are working fine.
I have a feeling it's to do with the last Jetpack upgrade?