SL restarting my PC for a pastime.

Since the upgrade...and the attempts to fix the texture loading / lag problems SL will restart my PC due to the slightest increase in activity. I now have graphics down to a minimum (worked fine before on high) and clear the cach before every entry. However it is usually now only a matter of minutes before SL takes down my PC. This is unacceptable and if a solution can not be found I will have to give up on SL...it's no longer an enjoyble experience. I too vote to return to the previous build...this latest version has brought nothing but misery...