I have the same problem as described here.
I've installed SC2 on two systems, one
had this "Insert DVD" problem, the
other did not. I deleted all of the
files and re-downloaded on the system
asking for a DVD and it still asked
for the DVD. I tried moving the files
out of my home directory as suggested
by another user here and it worked.
Out of curiosity I tried moving the
files to somewhere other than
/Applications (I used /Users/Shared)
and it still worked. The one thing
that comes to mind as a difference
between my two systems is that the
system where I'm asked for a DVD if
the files are in my home directory has
Filevault (home directory encryption)
turned on. The system where I was not
asked for a DVD does not have
Filevault enabled. I wonder if the
installer is confused by Filevault.
I'm wondering if someone here had the same problem and found a solution to this.
Best Answer
I just found the solution here: http://us.battle.net/sc2/en/forum/topic/166496671#9
You have to either disable FileVault (not recommended) or just move the installer folder to another location, which is not encrypted.