Mr. HEFED,
Thanks a million for bringing this PD display problem to the forum. I have been searching off an on for a couple of YEARS to find out exactly what method Power Director uses to display videos in imbedded preview mode. Like you, I too was concerned because my raw videos were always darker in imbedded-preview than they were when the viewer was detached, or when they were viewed in Windows Media Player, VLC, etc..
Even though I'm pretty sure that it's some kind of Cyberlink proprietary Rendering Codec issue, I couldn't find any way to locate-isolate and disable this mysterious varmit. Eventually I just learned to not adjust the brightness controls as dramatically and the resultant DVD turned out OK. BTW... I'm still running PD9, but come to this forum to learn if PD11 is better. If this "dimmer preview window" issue gets fixed, it will be (for my modest needs) the #1 best reason for an upgrade to PD11.
Thanks again for having the saavy and initiative to bring this issue to the forum experts, Mr. Hefed.
-Allen in Chicagoland