This may be a bug in the new Dashboard. When try to change the dimensions of an existing player and save the changes it reverts back to the original size. Also in the "Integrations" tab under "Custom Properties" I see the description but there is no box to enter a property.
I am using Windows 7/IE 9 if that helps.
Thanks,
Avi
This works fine for me under Vista/IE9, so I suspect there might be some issue with your browser. You might want to try logging out, cleaning your cache and logging in again.