I have an evaluation version of Confluence.
When I click on the Comments textbox it says Loading the Editor but it never gets loaded, no error message either (not even a timeout).
This is happening on Confluence 5.01, Safari 6.0.2.

Thanks!

Update: I just realized this is also happening on Chrome 25.0.1364.152 (latest version). It worked before, but I restarted the Confluence server and it seems it stopped working. The Comments editor loaded on IE8 but after a minute or so.