Yesterday's discovery was that I finally noticed that Model Views retain the annotation scale that is current at the time the Model View is created (when using the VIEW command). I did this while using ACA 2010; it may also occur in 2008 and/or 2009.
After drawing an appropriately sized viewport on a Layout tab and using the VIEW command to restore the Model View I created in that viewport, the viewport scale is correctly reported as 1/2" = 1'-0" on both the Viewport Scale control on the Drawing Window Status bar and on the Design tab of the Properties palette.
Unfortunately, the View Manager dialog does not provide a way to change the Annotation Scale property once the a Model View is created. You can rename the Model View, update the layer snapshot saved with the view (if any) and edit the boundaries of the Model View, but, as you may be able to tell from the gray background in the first image, the Annotation Scale property is not editable. I had hoped that while editing boundaries, that I would be able to change the annotation scale using the control on the Drawing Window Status bar, but that control is disabled when editing boundaries. In order to change the scale, you have to recreate/redefine the Model View, with the correct annotation scale set current prior to the redefinition. This is a fairly straightforward process, but it does require you to reselect the Model View boundaries.
- With the Model tab current, set the desired annotation scale.
- Start the VIEW command. In the View Manager, select the Model View to be recreated in the left pane, and then select the Name in the middle pane and copy the name to the clipboard. (You can skip this step if you are willing to type in the exact view name in the next step.)
- Click the New button. In the New View / Shot Properties dialog, paste (or type) the view name in the top edit box. Make any other changes to the settings in the dialog as desired.
- Click the Define view window button (or select the Define window radio button) and define the area of the Model View.
- Click OK in the New View / Shot Properties dialog. Choose Replace in the View - Already Exists dialog.
- In the View Manager dialog, note that the Annotation Scale property for the redefined Model View now matches the current, desired annotation scale.
- Click OK to dismiss the View Manager and register your changes.
- Return to the Layout tab and restore the redefined Model View in the viewport. Notice that now that the correct annotation scale is associated with the Model View, the viewport gets the correct annotation scale when the Model View is restored.