When it happened to me I was told to make sure there was a home link on the root, linking to the
www.homepage.com and that the bot would pick that up and spider it properly.
So remove the URL, then readd it after making sure there is a link to the root with www. in it.
I cant say for sure if that's still the fix.
EDIT - If ya had ICQ we could have settled this easier. (jk)