What web browser is this happening on? Are there any browser plug-ins or extensions active on that browser?
The Dashboard interface is a bit slow/sluggish, especially when it first loads. Been a complaint some have made in the past. Here are some of those past threads:
http://community.wd.com/t/very-slow-dashboard/96730
http://community.wd.com/t/extremely-slow-dashboard-response/93593