On 09/20/2013 12:55 PM, Les Howell wrote: > Any ideas on what could be the problem? Have you tried the Magic SysRq Key? (https://en.wikipedia.org/wiki/Magic_SysRq_key) If it works when you test it, but not when you need it, suspect hardware problems. I had that happen last year and it turned out that my CPU fan was on its last legs.