Since the incoming resolution is high (the benefit of Blu-Ray), and the digital signal on HDMI is set, the film mode processing becomes unnecessary. It can't improve the picture more because processing the incoming resolution would more likely reduce the quality of the picture than the ability to enhance it.
In short, processing that particular signal on that particular input is redundant. Your TV is telling you that it recognizes the signal as a good signal with a great resolution, and that feature isn't going to help improve it any more than it already is.
I have the Samsung HP-T5054 TV. I just got an Insignia Blu-Ray player(NS-2BRDVD). I have it connected to the TV with an HDMI cable and optical to a Kenwood sound reciever. The problem I have is in the TV setup menu I am not able to select the film mode. I have film mode selected to on in the Blu-Ray player settings but in the TV menu the film mode option isn't highlighted. Does anyone possibly know why I am unable to? In the picture mode, I have tried all the possible settings and none will allow film mode to be highlighted. Thanks for any help.