Hi, First Merry Christmas Second, I'm facing the same issue that the one described here : http://lists.boost.org/MailArchives/ublas/2007/08/2247.php As I didn't found a reply, I'm posting new one. I'm runnig version 10.34.01 and using ublas for a linear least square resolution problem. the error was : -------------------------------------------------------------------- ...ublas/storage.hpp at line 196: i < size ** std:exception ** bad index ------------------------------------------------------------ It seems to be a resize() problem on matrixes, any suggestions? Thanks