I'm wondering if I made a serious mistake here. I just ordered more RAM for my Mac Pro, 4 GB total with 2 sticks at 2 GB each. Then I thought to check "About this Mac" and it says I have 4 sticks at 1 GB each. Will I be able to have 2 sticks of 2GB RAM right along with 4 sticks of 1GB RAM? Or do I need to cancel my order? Thanks.