If you merely use the download link at Vicibox.com, you will get the latest version.
But the word "stable" is deceiving. This is the INSTALLER version, not the software version.
Vicibox is the Installer for Vicidial. Vicidial is the actual software being installed. At present the "Latest stable" is technically 2.4 for Vicidial and 2.6 is the Developer Trunk. However: All our clients recently have been using the 2.6 developer trunk and have had no stability issues whatsoever. Not to mention they get the latest toys with this version.
When Vicibox installs Vicidial it will install the latest version (today's version! with any improvements committed to the base code up to the minute at the moment of your installation).
http://download.vicidial.com/iso/vicibo ... nstall.pdf