Sorry for the confusion. The Richtext editor is actually a separate program, embedded within Moodle.
http://richtext.sourceforge.net/
It's not currently possible to use the Moodle translations with Richtext, so it has it's own file of translations. These are the ones I alluded to. Some related discussion is here:
http://moodle.org/mod/forum/discuss.php?d=1181
To get the editor when adding a resource, you need to specify "HTML text" as the format on the first page. If you choose "Plain text" then you won't get the HTML editor, you just get a plain text field.
On top of all this I found a little bug on the resource editing page that would produce
Javascript errors in IE when the Richext editor was enabled and the user is editing plain-text or Wiki-text resources. This bug has probably been there a long time - and sounds like one of the things you encountered. I've just fixed this in
CVS, here is the info if yuo want to patch your own installation:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/moodle/moodle/mod/resource/details.php.diff?r1=1.13&r2=1.14
Does all that make more sense?