Are both sticks of memory the same brand? Sometimes they don't like to be mixed.
You may try removing one and see if it is stable. If it is then swap and see if it is the same with the other. If it fails with only one, then that one may be bad. Make sense??
If it fails with both, one at a time, then it may be something on the mobo or something else. Unless both are bad, not likely but possible.
Did I say that so it makes sense? I have been up all night.
One eye closed already.
Later.