In the Chart Data table, when I enter a "-" followed by a number and apply it 
to the chart, OO treats it correctly. However, when I enter a number followed 
by a "-" followed by a number, OO instead applies a completely different, 
arbitrary value to the chart in its place and changes the data field in the 
table to that value.  To reproduce this:

1.) Select the "Insert Chart" option, either from the toolbar or the "Insert" 
pull-down menu.
2.) Right-click the chart and select the "Chart Data" option.
3.) In the data field of Row 1, Column 1, type exactly the characters within 
the quotations "9 - 8".
4.) Click the "Apply to Chart" button and observe the chart.

When I did this, I got the value 37872.  I also reproduced this in Windows 98.