I recently specified a chart to be the default format for x-y charts. I'm
not sure why, but now when I create a new x-y chart, the plot area is
miniscule -- less than the size of a small postage stamp at 400% zoom! It's
too small to even select, in order to resize.

Can anyone tell me how I can fix the problem, including changing the default
chart to one with a reasonable-sized plot area?

Thanks.