www resolving on main site

So, the site http://probizservices.com/ is the main site in a multisite install with Buddypress. I am using domain mapping. On some computers, when one types in http://www.probizservices.com, the site fails to load. I've checked dns settings and there is a cname record for www pointing to probizservices.com.

This isn't a support question, just looking for some ideas.