Upgraded this site to TxP 4.0.2 (or thought I did).

*First mystery:*
When I told my usual FTP client to upload the updated files, *seventeen* of thirty-six simply failed to do so. I knew something was wrong when the main TxP page for writing articles was obviously broken. The old files were still there on the server (you can check the revision numbers right there in each text file).
Sencer and Zem at the “TxP support forum”:http://forum.textpattern.com/ were great, and uploaded the current list of revision numbers to the “TxP FAQ”:http://textpattern.com/faq/ on the _same day._ Great support for a free product.

Eventually, I had individually re-upload the correct files, and most things started working.

Personally, I think this was an FTP problem, either my client or the server let me down. More on this later.

*Second mystery:*
The images were _still_ not showing on the site.

This one was totally my fault. I was supposed to manually upload the site-design images to /images, rather than loading them into TxP. I choose this arrangement so that the markup can be more semantic. For example, background: url(/images/background.gif); rather than background: url(/images/4.gif);

*Third mystery:*
Creating thumbnails of images still throws errors. I’m sure the experts at the forum will help me fix this one too.

So the site is working. On to the content!