Upgrade to 3.4.3

After downloading 3.4.3 I open the dmg file. Instead of mounting a volume called “OSBoot”, I do get one called “aTV Flash” If I continue the installation I get a message that says " unable to find volume “OSBoot” Any ideas?
Jim

There is a second file required for the installation. Please read through the installation guide that was included with the aTV Flash installer.