but using 3.6, for me, isn't an option anymore after April 24th.
I just had a look at http://www.tiddlywiki.com/ in IE6 on Windows XP
and got the same error.
What has happened is that a fix has been made to TiddlyWiki that
inadvertently broke IE6 compatibility (generally, TiddlyWiki works OK
on IE6 and IE7).
I'll try to investigate more, but for the moment, as others have
suggested, it would be best to try working with another browser or an
older version of TiddlyWiki. (There is an archive of old versions at
http://tiddlywiki.com/archive/)
Best wishes
Jeremy