Why are frames being dropped during encoding?
Try increasing the bandwidth for the session and reducing the frame rate and frame size. In addition, if you are sourcing from devices, check that you are using capture cards that have been tested for use with Windows Media Encoder 9 Series and that the current drivers for the cards are installed. Finally, the encoding system may not be sufficiently powerful. Try optimizing the system by closing all other applications while encoding, turning off video preview and postview, and adjusting the performance settings. For more information about achieving optimal system performance, see Windows Media Encoder Help.