I have a stacked bar chart that I put together. When I change a specific value on the horizontal axis most of the bars seem to vanish. The values are based on a series of month/year dates. In the attached sample, change the word "test" in Cell AW4 to the correct date (12/2010) and watch what happens to the bar charts. They all seem to vanish except one. I have constructed this bar chart several times and still come up with the same problem and it seems to always be the values in the vicinity of AW.