Bubble Size in a Bubble Chart

I seem to not be able to get the size of a bubble to change. In my test, I am passing 4 records:

1,1
3,4
2,3
2,3

My bubble chart correctly shows a bubble chart with 3 bubbles at 1,1 ; 3,4 and 2,3 but I had expected the bubble at coordinates 2,3 to be larger… What could I be missing?

I found what I was missing… No need to reply