update graphs

I have an Access 2002 database that tracks tire performance, comparing tread
depth against distance travelled or time in service, and generating wear
rates. One of the reports is a Tire Record Card (TRC). The TRC lists
mounting, demountign and inspection details, and has a graph that shows the
wear rate trend line. Each tire in the database has an individual TRC.

The problem occurs when running the TRC reports for several different tires
at once. Access tends to take the graph from one TRC and insert it into
another TRC. For example, the wear rate graph on the TRC for tire ABC is
correct, but then the graph for tire ABC is also on the report for tire XYZ.

My explanation is clear as mud, to be sure, but I definitely appreciate any
help I can get to solve this.