The selection anchor or endpoint seems to get changed incorrectly when switching between Thumbnail and Preview modes. As an example: !) Select the 1st image in a thumbnail view. 2) Double-click the image to enter preview. 3) In preview, click the 2nd image in the filmstrip. 4) Press ESCAPE key to return to thumbnail view. The 2nd image is selected. 5) SHIFT-CLICK the 4th image. Images 1-4 are selected. Only images 2-4 should be selected. Note that if step #3 is changed so that the 2nd image is selected by using the RIGHT-ARROW key, the selection in step 5 will operate correctly. It seems like there is a difference in how the selections are registered depending on whether it is a mouse click or an arrow key.
*** This bug has been marked as a duplicate of bug 281742 ***
Fixed with #281742 and not reproducible with 6.2.0