after investigation, I found why some configuration of XP sp2+ crash with some packers/crypters : DEP, Data Execution Prevention, the Microsoft protection built in to XP SP2+.
If activated for all programs and services => crash. It's possible to set exceptions
If only activated for windows programs and services => ok
I'm certainly not the only one XP user having DEP turned on !
Control Panel->System->Advanced->Performance->Settings->Data Execution Prevention