Hi Wade,
Not a light shroud problem, most planets are so bright the light getting into the tube has little effect. The problem is possibly aperture or magnification.
Aperture: more aperture will give more resolution which in turn means you will see more details. My 12" collapsible shows dark areas on Mars as well as the ice caps. However, this is generally at HIGH magnification
Magnification: The more the better on planets, The theoretical limit for magnification is 2 x the aperture of the scope in mm, therefore, yours would be 400x which, if your Focal Length is 1200mm (from the website) means you will need a 3mm eyepiece to get that level of magnification. Now this is generally uncomfortable to view with a 3mm, so you could use a 6mm with a 2x barlow to get the same magnification or any other combination (10mm with 3 x barlow) etc.
You can see similar views that I have achieved in my webcam pics with a 5 inch scope
here which was starting to push the limit of the details available from that scope's resolution capability.
Try a 10mm with a 2 or 3 x barlow and see what you can get, best thing is to borrow one from a friend or colleague at a viewing night to see if your scope has enough resolution to make out more than you have been able to see up until now.
Cheers
Chris