finally i have found the problem!!
the memory usage is not the cause
i have also tried lavsplitter with combination of various video decoders but nothing..
i have installed the same programs (SVP, C++2008, avisynth, ffdshow etc) on my other computer with phenom dual core and an nvidia 8600 and all things goes perfectly without errors (the performances are very low with 1080p)
this old PC is very "messed up" and not up to date (windows vista)
then i returned to my new PC and i disable the GPU acceleration ( the video card is the only important different element) and all works fine without errors
In real time if i activate GPU on SVP Manager the Potplayer immediately crash with famous kernelbase error (only if there are activated motion estimation accuracy or blocks overlapping)
now, with GPU on, potplayer crash also with shader23 and motion extimation at half pixel.
my last try will be to roll back to 11.9 and if errors persist i definitely will buy a nvidia 560
thanks for your advice and availability that allowed me to understand the problem