pie_risks.gif with a pink background?

[Scott C. Kennedy]

When I do a nessus scan with the command line flags to create an HTML
report with Graphs, I get the strangest output...

All graphs look normal, except for the pie_risks.gif graph comes out with one
red slice, a pink background, and black text. So, all other slices of the pie chart
are pink on pink (thus invisible).

Any ideas?

Scott