ScienceBlogs say they’ve upgraded their Rackspace package in a hyper-whizzy way, which is supposed to have fixed all the problems with IP blocking.
If you’re still having trouble, err, and can’t read this message, err… ahem, or perhaps you have a friend, yes that’s right, or maybe you can read this from work or not from home, anyway, please mail the failing IP to email@example.com.
Apologies for all the inconvenience. When/if I ever work out exactly what was going wrong, I’ll let you know.
[Update: I'm pleased to say that I at least can now read / write SB from home.]