5 October 2011 at 12:04am
Are you saying that the specialpage_popup.ss template itself actually includes the page header and footer? In that case removing them from the file and doing a /?flush=1 should do the trick.
Or do you mean they are not in the template but for some obscure reason SilverStripe still includes them when generating the popup? In that case: are you sure the specialpage_popup.ss is actually used? If so then post your specialpage_popup.ss template and of the bit of code in your popup() function where you generate the output...