SOLVED--Downloading Wrong OS

This is confusing: I have downloaded Zorin, both standard and RC, burned them to a USB drive with Netbootin, and booted. In every case what boots is Linux Mint 13 (Maya), which is not on any of my drives (I do have Mint 12 installed). Have I been infected with a magic computer genii, or What? I'm very eager to try Zorin.

I reformatted the HD on which I was booting Zorin, and magically there was no problem. Somehow, I guess, when the program searched the drives it found something I didn't know was there. All is well now, and thanks to those who helped.

Curiouser and curiouser, as Alice in Wonderland said. I burned the iso to a DVD in the thought that maybe it was my thumb drive that was screwed up -- same result. Then I booted on another computer that had Windows XP: The boot was perfect and I had a live Zorin to work with.
Back to this computer. During boot there are messages that it can't find "/root/preseed/[etc]." Then it can't find a bunch of other files: "no such file." Then I get "searching disk for index" and a very long pause (about 2 minutes) while my hard drives are apparently being searched, then it boots into a Linux Mint.
I see that the kernel line has "file=cdrom/preseed/[etc]." Is this the problem? I'm reluctant to give up on this one.

Zorin 6 Release RC:

http://www.zorin-os.com/releasecandidate.html

Regards Wolfman