I am a joomla newbie so apologies if this is something obvious.
I am trying to remove the -2011100528 from the url so it just uses the alias I defined. (http://www.screenlaunch.com/contactus-2011100528/
Is there something I am missing as I thought it would just use the alias name unless it had non latin characters?

It's only needed if you need to add your site to Google news which require a unique URL identifier.