Thanks Larry.

I wondered if it should auto-install again, but no sign of that.

I am using Zen 1.5.4 and I assume the latest version of CSS/JS Loader - I downloaded it from the Numinix website a few days ago. I can't see any version information although the zipped direcorty has the suffix - 89cbf0a

Shall I try reuploading the files?

Cheers