Graph not refreshed (reporting services 2000) - urgent - CalvinK

Hi all,
I have a graph in my report and I've setup a temp folder on the server to
temporarily hold the image of the graph being generated. However the problem
is that whenever i change the report criteria (via the website which hosts
the report), everything else on the report refreshes to reflect the new
criteria except the graph itself. It seems like the image created when the
report was first generated persists and the report keeps "re-use" the same
image, regardless of the subsequent changes to the report criteria.
This only happens when the report is hosted by a website. It seems to be OK
if I work directly off the Reporting Services DE.
Does anyone have any suggestions that might help or point me in the right
direction?

Many thanks in advance,
Calvin