The AMS does not support H.264 RTMP Stream with 2 B-Frames

we are using Adobe Media Server 5.0.3 Pro version.

we push a H.264 RTMP stream to the server , if the stream is IPPPPP....PPP and IBPBPB...PBPB , the Player ( JWPlayer or VLC ) is correct , but if we set the stream to IBBPBBP....BBP, the player drop some frames .

is there anything limit with Adobe Media Server ?