It sounds to me like you have some REALLY dirty memory slots. Get a can of compressed air and blow it out real good. And then get a Qtip and clean connections with alcohol or electrical cleaner. There is no reason why it should not be able to take both memory sticks unless they are so gooked up that it won't fit in. Or one of the slots could be bent but that's doubtful.
"Sort of" is harmless "Sort of". Is a filler. But sometimes, "sort of" means everything. Like after "I love you" or "You're going to live" or "It's a boy".