May 28, 2014, 02:07:49 am
I think the first problem is that you are using an earlier version 3 Free. You need to be using version 3.2.1 Free.
Shadow settings - Sun Shadow Range, Shadow Correction and Shadow Slope need to be set to suit the scene and GI being used as well.
It's hard to tell why you get flickering without knowing what your settings for Shadows and GI are. It's the same flickering issue for both GI and transparent materials. Can you post some screenshots.