Basic 10
Well, the challenge does work, I just completed it again myself. I'm one of the ones who happens to not need a proxy, so I don't know if I'll be much help here.
The IP address that I can get in with is 207.6.16.***, so my only guess is that the script is telling you the wrong range, or telling you a much bigger range than it's actually looking for (I can't tell because it won't show me the range from my IP).
%5bquote%5d%5bb%5donejerlo+wrote%3a%5b%2fb%5d%0aMy+IP%3bas+seen+on+whatismyip.com+is%3a%0d%0a%0d%0a219.64.77.23%0d%0a%0d%0aWhich+is+well+within+the+IP+range.%0d%0a%0d%0aI+even+did+a+graphical+trace+route+of+my+access+route%3a%0d%0a%0d%0a%5bimg%5dhttp%3a%2f%2fimg291.imageshack.us%2fimg291%2f5872%2fgraphws.th.jpg%5b%2fIMG%5d%0d%0a%0d%0aI+still+get+the+error+in+basic+10%3b%0d%0awhat+am+I+doing+wrong%3f%0d%0a%0d%0aAdded%3a%0d%0aSorry%3bs**tty+work+on+the+image.+%0d%0aThe+trace+route+isn%26%2339%3bt+of+much+use%3bbut+it+looks+nice%21%21%3a%29%5b%2fquote%5d