Screen flashes when PlayGui loads...

Hi, when the PlayGui first loads, the screen flashes, and then settles down. We need to get rid of this visual artifact. We would like to keep the Loading screen up until we are actually rendering good data. Has anyone looked into this? Ideally we would want some sort of event which tells us that terrain paging is done, and everything is really ready to be rendered, so we can transition from the loading screen to the PlayGui screen with no flashing in between...Thanks!!