Sorry for the delay in replying. I have been off work over the Christmas period.
After trying the advice I have managed to work out what was wrong. When using Dynamic data the chart_data.asp file was trying to look for the connection settings in the folder ../Connections/IPC.asp
Of course the connections settings are stored in the root of my site so when I copied the Connections folder into "DynamicWebCharts/Data/" folder on my site everything worked!
Thankyou everyone for your help and advice it is much appreciated