Your public html folder's htaccess, does it have a .txt extension? I believe upon first installing, it bares that extension. >.> I THINK.
If that's not it, could it possibly be relative to this:
http://www.mysidiaadoptables.com/for...ead.php?t=4763
I understand your issue isn't a blank page, or I'm assuming it isn't, but it may help. Not certain.