YASBO (Yet Another ScrollBar Oddity)
xemacs -vanilla &
C-x 5 2
C-h t (for example)
In the tutorial frame, grab the scrollbar, move it down to a random place, and
release it *with the pointer in the same frame*. Now if you move from this
frame to the other you'll see the scrollbar move and/or resize itself. This
does not happen if you use the scrollbar arrows, or if you move the pointer to
a window that doesn't belong to XEmacs. You really have to leave this window
and enter another window of the same XEmacs.