You might want to update in the stylevars:
- profile_content_friends_list_hover (currently I quickly set this to #333333 or rgb(51, 51, 51))
- navbar_popup_link_background (aka "Navigation Bar Popup Body Link Background Color")
Noticed that those 2 on the least are showing a white background when popping or hoovering

.
As for the white background in the wysiwyg on IE, seems like a flaw in the javascript I guess, because if you switch from wysiwyg to normal then the problem is solved. Though the annoyance are the inputs of title and tags, black text in a dark-gray field. kinda hard to read and tested on 2 different monitors.