I have a problem to put a dimension on a 2D sketch. This thing started to happen today after my solidworks 2012 broke down during a "smart fasteners" operation.

Now when I try to dimension a sketch, as described in:

http://help.solidworks.com/2012/English/SolidWorks/sldworks/Dimension.htm

In the step 2 is said "As you move the pointer, the dimension snaps to the closest orientation."

But I have not a dimension to move, it only appears at the time when I click in an other site, and I can't move it. Is something wrong with my system configuration?

Thanks.