Revit Architecture 2011 - Masking Region Jump

[thalim]

When I select a masking region on the sheet by activating the view, the object jump as soon as I touch it.
Does any one run into the same problem and can it be fixed?
The Video Card is ATI Fire GL3400.

[RevitRonin]

Maybe it's the Press & Drag option on the lower right of your screen. Uncheck teh box.

My problem is that sometimes Masking Regions just don't mask in the sheet views.