I have narrowed some of the issue down in IE the following conflict was reported.
Webpage error details
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.2; .NET4.0C; Tablet PC 2.0)
Timestamp: Thu, 17 Feb 2011 20:46:50 UTC
Message: Object doesn’t support this property or method
Line: 286
Char: 434
Code: 0
URI: https://…/wpress/wp-content/plugins/nextgen-gallery/admin/js/jquery-ui-1.8.6.min.js?ver=1.8.6
This occurs when both the Next-gen Galleries plugin and Propel plugin are activated.