 <p>Does the machine running IE 6 have its security settings set to reject cookies? Alternatively, if you are using one of the various techniques that supposedly allow you to run multiple versions of IE on the same machine, be aware that the results are not perfect, and often cause subtle aspects of the browser to break on one or more of the versions: for example, see <a href="http://tredosoft.com/Multiple_IE#comment-1843" rel="nofollow noreferrer">this comment on Tredosoft's Multiple IE page</a> about cookies failing in IE 6.</p>