This problem highlighted by using sleep is an underlying memory fault, so you could avoid the problem by not using sleep, but the problem is still there and could cause issue in other operations where the Ram was sufficiently stressed.
I had the same issue last month with a system and it came down to using Ram the motherboard and i7 controller wasn't totally happy with.
You could try turning down the Ram frequency in the bios, but you would of course have to be able to faithfully reproduce the fault to debug it.