The scroll wheel works on initial start-up, but once the round-trip is performed, it ceases to work on the folders section as noted by others. Nevertheless it still works in the other sections on the LH side. In fact, starting in say, the collections section, it allows scrolling until that section disappears and then just stops. Win 7-64bit.
Scrolling seems to be an area that doesn't always work as well as it might; this is also evidenced by the lack of control in the keywording list when attempting to move keywords up and down the list.
Anthony.