All popup IFRAMEs are created with attribute
scrolling="no". If the content inside the IFRAME is "bigger" than the actual modal view (in it's maximum size), user should be able to scroll the content. This works properly in Firefox for instance but Chrome ignores the
overflow-y:scroll CSS and disables scrolling of the IFRAME. There are possible CSS fixes available but none work nicely in all browsers.
Suggested fix is to set scrolling attribute to 'auto' as it's the default state and only explicitly set to 'no'.