We have problem with optimization. If him active or set -O3 optimization after some time encoder generate output that cannot be decoded on some devices but not all devices stop decode. If we set -msse3 all work fine with any optimization (-O3,-O2,-O1). If set -msse4.2 and -O2 works better but still happens from time to time the same. We try icc version 12.1.0 (gcc version 3.4.3 compatibility) RHEL4 32 bit, Intel Xeon CPU E5645 @ 2.40GHz. As i understand problem in MPSADBW instruction or something more?