Scroll Bar scrolling issue in Sequence Editor

[stringtheory]

I have been finding for quite some time now (several versions of DP...) that in the Sequence Editor, at magnification levels higher than 4 bars being shown in the ruler (i.e. the ruler shows numbers every 4 bars or fewer), clicking in the scroll bar causes the screen to jump 2 window frames left or right. This only happens when there is data in the SE, if all the data scrolls out of view the scrolling works correctly, moving only one window frame at a time.

I've set key commands to "scroll left" and "scroll right" and these work properly. Anyone else noticing this?

[bayswater]

No. If I set the zoom so three bars are showing (bars 1 to 3), clicking on the scroll bar moves the display to the next three bars (3 to 6)
There is a OS X system pref that sets what happens when you click in the scroll bar, either next screen, or to the relative position in the document. I wouldn't have thought this preference would apply to scrolling in an application, rather than the Finder, but could that be it?