A thread at WebmasterWorld named Google's response to: Redirected URL discusses one members experience with a backlink, that she believes, was responsible for de-listing here site in Google.
She was listed in a directory that was using a bunch of redirects. I am not sure which directory it was, and why she would believe that her exclusion from Google would be from a directory listing but she does. Obviously, she knew something was a bit sketchy with the directory. :)
The reason I note this thread is because of jdMorgan post (moderator at WMW) msg # 8. I'll quote some of his post here:
To clear up some points here, the first thing you need to do when considering a listing in a given directory is to use the server headers checker to see what kind of redirect(s) the directory uses on its links. Examine the output of that utility, and look for the server response code. A 301-Moved Permanently is acceptable. A 200-OK or a 302-Found (Moved Temporarily) is not acceptable. You will get a 200-OK response for pages which contain a meta-refresh (not good). Multiple redirects are not good, but could be acceptable (I don't know - see final pp below), but starting with the listed URL, follow each redirect manually with the headers checker, and note the response code and the URL being redirected to, entering each URL into the headers checker in succession to "follow" the redirect path.