Earnie said:
I have no reason to know why Acquia would have a different version of Drupal than a "regular version". Check the access permissions to the node. Empty the cache tables. Empty the sessions table. Empty your browser cookies for the site.
Oh why didn't I notice! They do do it differently. The Welcome Message in Acquia Drupal is simply a Page, and all you have to do is remove the Promote to Frontpage checkbox to have it stop appearing on the frontpage.
Thanks for the inspiration!