Chart Auto Expand Problem
 

For years, I've be charting temperature variations. As I added new
data points, the chart automatically expanded to accomdate the new
data. At 72 data points, the chart stopped expanding automatically.

Anyone know if this is a standard limit to expanding charts? Did I
accidently turn some feature off? Is there a way to fix this?

I'm running MS Win and Office XP with all updates.

Thanks

Mike