I am using Firefox 3.6.8. i ran your example file but i got the same output that i have been getting. It displays correctly in the designer but not when i run it. I have attached a picture of how it displays in each browser. Seeing that the problem must be local to me, could my settings be wrong. Your example is basically what I have in my page.
I have attached the code snippet as well.
Chrome version 5.0.375.99. IExplorer version 8.
SyncfusionExample_3f2e44fc.zip