Something strange happening in viewports

[wma]

I have a drawing set up with several viewports.

Each of these viewports is a crop of a design layer. In that design layer I have quite a few symbols, and each viewport crops to two or three of them.

I am finding that if I go into the design layer, and move one of the symbols, then when I go back into the sheet layer, and look at the viewport that shows that sysmbol, the symbol is drawn twice, once in its original position and also in the new position I've changed it to (ie. it is drawn twice over, on top of itself). This makes the drawing unreadable.

(Note that it is not drawn twice like this if I look at it in the design layer)

The only way I've found of resolving it is to create a new viewport from scratch. This is a pain because then I have to crop it all over again and also copy all the annotations over from the old one.

Does anyone have any idea what is happening here?

[Pat Stanford]

Several guesses/questions.

1. Does the viewport have a red dashed border meaning it needs to be updated? If so, have you updated it?

2. Could you have possibly duplicated the viewport and have an updated one sitting on top of an un-updated one with the old location?

3. Could you have duplicated the design layer and the viewport is set to show the original and duplicate layers, but when you are looking at the design layer you are set to acitve only or have the duplicate layer turned off?

[wma]

It was no. 3.

Obviously I made a duplicate layer at some point, which contained the unrevised drawing and which for some reason was set as visible in that viewport.

Thanks!