To reproduce, on IE:
- login as administrator
- add the spaces macro in a page:
- open that page in inline edit mode
Technically, when the spaces macro is displayed in a page which is edited inline, the create space form that is generated by the macro causes a form to be nested in another form. This doesn't make sense HTML wise, it is a warning of the HTML validator (not an error) but messes up the DOM on IE (yes, this is the word, I don't have an explanation for what happens), causing the form buttons (cancel, save, etc) to not find their parent form anymore, therefore the errors.
Also, this closing of the form too early (which I assume is what happens on IE) causes some extra elements to be displayed, which can trouble layouting in columns (in the case of a dashboard with a spaces macro on it).