Business Object -XI Crystal report Linking to excel

Hi,
I am new to this community. I am facing a issue while using excel sheet in crystal report as part of BO-XI. We have linked excelsheet graph to crystal report file but everytime when we preview report it shows same old graph. Even if we change the graph in excel it shows the same graph that was linked to it first time.

Please help in resolving this. Let me know if more information is needed.

Thanks,
Pranav Sharma