That build appears to be a beta version. AFAICT, 12A256 is the released version of 10.8.0. Best is to DL Mtn Lion from the MAS and try that.
I had downloaded this version from Torrent :-) So stood the problem !! And now on google search, I found it's Developer Preview 1.
Now, you know what happens when you muck around with pirated stuff. Stop using that illegal site.