Interspire Product Knowledge Base

Yes. You'll need to make a couple of minor changes.

Firstly, use the HTML entity of the character in your language files, for example: ˜

Such as: define('LNG_Summary_Graph_Unopened', 'Unope˜ned (%s %%)');

Then inside the admin/functions/stats_chart.php search for Arial and change to a different font such as Tahoma or Courier.

For a more information on these codes please have a look at this site