I am running Moodle 1.2 development (2004020300). The HTML editor works just fine if I try to update/edit an HTML Text resource from a Windows machine on my network. However, if I use a Mac OS X computer, running either Safari or IE (latest versions) I get a simple form page with HTML source displayed.
I think this is a network/firewall issue of some sort, ...
I don't believe it's a Firewall issue. I also use Mac OS X. The HTML editor does not work with IE or Safari. It does work in Netscape 7.1 for Mac.