Are you using Stuffit Expander to open those zips? If not, check the 'open with' triangle when doing a 'get info on the zip file, and change it to stuffit expander, if necessary.
I'm using Stuffit Deluxe 7.01, changed my open with setting from Stuffit Deluxe to Stuffit Expander, and it creates the blue and gray install disk every time.

Also, side topic, this version 2.7.1.3 seems to be finally taking us where we want to go. Now if we can just tone down the caffeine a wee bit, maybe I can browse and LW at the same time. That would be nice. Mine hasn't crashed yet, but of course I always disable that darned UltraPeer Crashin Machine.