Started using a Wordpress theme and unlike other themes I've used if you enter an invalid url www.domain.com/dfdsfsfd.html for example that url just shows the main index page but the garbage url stays in the address bar. Other themes I've used generate a 404 page for this. I'm worried this may cause problems with dupe content. Any ideas?
As far as I know MSN has an algo glitch/bug where your competitor can get you banned by making these pages indexable i.e providing links to these pages for the MSN bot to index, thus making it think its duplicate content from the same website thus mostly leading to a BAN from their SERP Yahoo and Google do not have this problem.