Hello Leo Lam,
The issue is caused by the fact that browsers on Mac do not visualize the Symbol font, which is used by default for the bullet signs. We have fixed the issue and the fix will be available in the next LIB (Latest Internal Build), expected next week, and will be part of the next official release - 2012 Q3 (due in few weeks).
All the best,
Iva Toteva
the Telerik team