This issue is caused by MDL-32506.

Even though the feature "Allow window to be resized" was determined to be an obsolete setting in MDL-32506, the removal of the feature now causes problems in IE9.
SCORM packages which were uploaded before the upgrade of 2.6 can still be resized.

New SCORM packages, uploaded after 2.6, are affected by the removal of this feature. The popup cannot be resized in IE9, which is causing tremendous problems for our users which are mainly on IE9. No issues in IE 10 though.

Please add the feature back in. IE 9 cannot be compared with IE 5.5. IE 9 still has a market share of about 9.5 (http://www.netmarketshare.com/browser-market-share.aspx?qprid=2&qpcustomd=0)