I'm not able to reproduce this result with a chart. I created a chart on my pc that has a standard ratio monitor (square) and viewed it on my iMac with a widescreen display. I did not see any difference, the chart was displayed with the dimensions I specified in the properties area after adding it to the page. Do you have a link or any other way we can see this? Have you tried this on any other machine than the two in question or with different browsers?