ahh... SM had nothing to do with versions previous to P7. I have had some issues with previous versions but was always able to find a work around or help from the kind people on this forum.

P8 SR1 is very stable for me so I would start to look at your hardware system if you are having problems.

My stable system
WinXP 32bit
Q6600 Intel quad
Asus MB
Nvidia GeF 9600 GT