Can you use the 'insert image link' button on the post box as whatever you're currently using is posting invalid HTML which is breaking the flow of the threads.
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.