I wanted to test latest OSMF version 1.6 and compiled the ExamplePlayer using Flex 4.5.0. When I start the player with FP 10,3,181,26, the video will played (can hear the audio and the playhead will updated), but the video isn't visible. Using Flash Player 126.96.36.199, video is visible!
I created three simple Video Players, one ActionScript based and two Flex based (one with MediaContainerUIComponent, one without). I tested all apps with both FP (10.3, 11). While the video of ActionScript based will displayed by both FP, the video of Flex based Players will not displayed using FP 10.3 but will displayed with FP 11.
Also the lastest release version of Flash Player (10,3,183,7) is behaving the same way.
I'm running MAC OSX 10.6.8 and tested with Google and Firefox.
sounds like it using stage video and the BG in flex is obscuring your video from being displayed. need to make sure there is nothing as far as any BG elements when stage video is on.
You can try putting the following in to force it to not use StageVideo since it is on by default:
OSMFSettings.enableStageVideo = false;
Somewhere early like in the app onCreationComplete