I am using Mac OSX 10.10.3 and have just installed Balsamiq 3. It’s working great but there are some things going on with the “Big” item scroll bar when using the mouse to horizontal scroll using the swipe motion on my magic mouse (not clicking and scrolling).
If I scroll right I can see the last items, but when I scroll left it seems to hide the first item. So I scroll back to the right and it duplicates the last “Big” item… then when going back to the left the second item is gone now. You can keep going back and forth and it goes on and on until all items are the same.
If I use the mouse pointer to click and scroll it functions as it should, but the above only occurs when using the swipe-scroll.
Going to another group and then back to the “Big” section it resets and all is well again… until I do my scroll-magic again.