The reference code currently doesn't handle payload extensions in SEI messages correctly. In SEIread.cpp, each SEI parsing function calls xParseByteAlign() before returning. The payload extension decoding code (in SEIReader::xReadSEImessage(), line 328) then reads the payload extension followed by another alignment. According to the spec, the payload extension should be read before any alignnment. The reference code only fails when there is a payload extension present, as the code at the end of xReadSEImessage() only runs if there are bits remaining in the buffer.

The solution is to remove the calls to xParseByteAlign().