JIRA Gadgets won't show pagination bar

When putting a JIRA Gadget in a Confluence page, the pagination bar won't be shown.
To make pagination appear, click the "gear" button and then "Refresh".

I noticed that the iframe that holds the gadget content's height is set improperly, after one clicks in "Refresh" link, the gadget content's height is correctly set.

It's possible to fix the problem setting the iframe height directly in Firebug too!