I have noticed lately that when I start a dimension change operation by clicking on one of the small black drag boxes, the dimension 'jumps' by 1/2 to 1/4 the current snap resolution. For instance, if the snap resolution is set to 1.0 (mm in my case), and the current dimension of the object I wish to change is 20mm, then when I first click on the drag box at the start of the drag operation, the dimension will 'jump' to 20.25 or 20.5 (or 19.75 or 19.50). The problem with this is that during the drag, the dimensions will change by the snap resolution value, i.e. 1.0 mm in the above example. This means that the dimension changes from 19.75 to 20.75 or 18.75, NOT from 20 to 20 or 20 to 19. This is very frustrating, as I normally set the snap resolution to what I want before starting the dimension change operation, and I expect to be able to change a dimension from, say, 20 to 23mm. Instead I wind up changing from 19.75 to 22.75 and then bringing in the ruler tool so I can manually edit that dimension from 22.75 to 23 - very annoying!
Am I doing something wrong here? Is there a way to avoid this dimension 'jump' a the start of the dimension change drag operation? It doesn't always happen, so maybe my technique is wrong, but I can't see how!