The poll is flawed, most of the users that haven't experienced SDS will not vote.There is no definite reason of what causes SDS. Some were on charger overnight, some were not on charger overnight, some were on table like mine in the afternoon, some with alarm, some without alarm, some in pocket, some in bed, some in toilet, some on stock, some on custom, some stock with custom kernel, some with custom and stock kernel. Only GOD knows what's causing SDS.
My replacement is 1.5 and still last 2 days it's conked off and i had to press power for 10 secs to make it boot up. I'm on XELLA but old bootloader. I dont think the s**tty bootloader is any cure for samsung's crap quality control on 16gb models. As you can see from the poll i started in the link in my signature about 49% of 132 users who polled have had their 16gb get SDS.
As bad as RROD on xbox360.
Meanwhile the users that did have the flaw are more likely to vote.
Even then, the number is quite high... it's concerning but I feel this thread is a much more contundent message that something is wrong.