Using MSDK 3.0 beta 2 I've run into the following two bugs:
(1) The "DecodeHeader" API returns MFX_ERR_MORE_DATA when being called with the following h264 header sequence:
00 00 00 01 67 64 00 33 AC 34 E6 02 C0 49 FB 84 00 00 0F A0 00 03 0D 42 3C 60 C6 68
00 00 00 01 68 EE BC B0
However, if I just add an AUD (00 00 00 01 09 10) to the end of that data, "DecodeHeader" is happy to do its job. Your own "MP4/AVC Decode using the Intel Media SDK" article/demo stumbles over the same problem. In that demo DecodeHeader always fails.
(2) After seeking in a VC-1 video stream, the very first frame output by your (software) decoder often contains block artifacts. The blocks are usually in areas where there's strong motion. The very next frame is clean. It's only the first frame which shows these artifacts. And it doesn't always occur, but very often. It occurs with and without "injected headers". If you need a sample to reproduce this problem, just let me know. I've seen the same problem with 2 very different files, though (one SD interlaced, the other Blu-Ray 24p), so I'm pretty sure it will happen with all files.
Here's a screenshot of the problem: