Errors in PP XP chart

[John]

Everytime I try to edit a chart in Powerpoint for XP, I
get an error message that informs me that Powerpoint is
shutting down and that I have lost my changes.

Sometimes the original chart comes from Excel and
sometimes it comes from Powerpoint's charting function;
there doesn't seem to be any difference between the two in
terms of the error appearing.

Is anyone familiar with this? It's driving me nuts.

All best,
John