Strange but true!
Went to sleep last night with 35% battery on Dorimanx 7.40, using extreme_battery + BLN, and this morning my phone had switched itself off!
Never, ever, had this before. When I re-booted, my battery was showing 29%.
Nothing was running or set on the phone out of the normal.
UPDATE
In a fit of pique, I flashed PhilZ kernel onto my phone, no ROM change, and my Home button has ceased to function!
I am aware of this happening when changing ROM's but not kernels. Am restoring a previous PhilZ nandroid to counter this.
OK... my bad. I forgot to press the HOME button restore in STweaks.
I'm not alone with the shutdown problem it seems, see
here.