YOu need to put the url in the box and then if it is an image like the charts you need to click on the insert image link - try that and see if that makes a difference,
digger - you seem to be doubling up the img source part at the beginning of the tag - I have just removed this from the second chart and it displays fine
There is no difference and disregard what I said about the link box below - to do it correctly, just copy and paste the link directly into the body of post where you would enter your text.