I’ve been told on my blog host’s support forums that I’d been using a 10 year old fixed-width theme. With my question on the forums having to do with the appearance of Facebook posts here, I’ve had to change to a more updated theme, and the P2 theme seems to suit my current needs. The header graphic is smaller and now appears at the top of the sidebar, but the sidebar is still visible in all posts and pages. More importantly, full Facebook posts do show. Let me know on Facebook how you like it.