Open your site and then go to Tools/Page Options and click the Compatability tab.
Change the Browsers, Browser Versions and Servers dropdown and look at the changes to the options below.
If you want cross-platform operation, select Both on Browser and then select what version you want to support.
There are just some features that work in one, but not the other, and there is nothing we can do about it. So you have to pick a middle ground.