Body macro properties cannot be edited in IE

Steps to reproduce:

• Add the {info} macro to a page
• Click on the macro placeholder to get the property panel
• Click the 'Edit' option

Nothing happens in IE8 and IE9. Expected behaviour is that the macro browser opens, to allow the user to change the parameters of the macro.

This works correctly for non-body macros, it is only macros which have a body which fail.

This works correctly in all other supported browsers (including IE10)