On 07/04/2012 03:29 PM, Duijneveld, PW - SPLXM wrote: > Program runs fine with no optimization, fails with O3 Please send a complete test case. > I thought that unsigned char and char were equivalent? They're not. > This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. We can not help anyone who sends messages with such a disclaimer. If all of your mails must send this because of a corporate rule, please use a webmail system. Andrew.