How do you 'reset' an Excel chart via COM?

Hi Folks,
I'm using an embedded Excel chart in an application which the user can
change (via combo) what they want to graph. How do you reset the graph
between selections? My original idea was simply to delete the graph and add
a new one, but this produces an obtrusive dialog box. The other option I
tried was to delete all the series from the series collection and then add
new ones. This almost works, but when you come to insert new values in the
series, Excel comes back with unable to set the value property?

Also rather weirdly in Delphi at least, when my company upgraded to Office
2K, whenever an instance of Excel is created it seems to stop on a
breakpoint within Excel?! Is this normal?

--
Regards
Rob Pollard

My Astro CCD page is:
http://www.robpol.demon.co.uk