Build 2003030408 works fine. Build 20030307 and 20030308 (I don't recall the last two build numbers) crash on startup (and as soon as the pref is changed) if directorylisting is changed to XUL. Open new profile edit/preferences/debug/networking Change directory listing from HTML to XUL Click OK and application crashes, subsequent loads of profile crash.
Sorry for the spam, browser hang. *** This bug has been marked as a duplicate of 196477 ***