It sounds to me like a "chicken and the egg - who came first?" kind of thing. Did you do this install from the "one-click" installer on Dreamhost, or did you install it yourself?
Generally speaking, after you complete the first "running" of the install files, they write your "new" config file, then you chmod that file so it is not "re-writable", and then delete the install directory. It sounds like you don't have "config" file that zencart considers to be "installed", so it tries to fun the "install", which you have already deleted (which would explain your "not found" message).