To reproduce the bug, open a directory with few files. In the white area in the right panel, press and hold the mouse left button. Move the mouse up. Xfe crashes as soon as I reach the last file/directory in the list (or the ".." parent directory in an empty directory).
If I do the above really fast, it may not crash. But usually it does.
Also, when it doesn't crash when moving the mouse up rapidly, if I keep button held and move the mouse back down it crashes again as soon as it reaches the lowest file/directory in the list.
This bug was not present in version 1.33.
This is on FreeBSD 9.1. Can you confirm the regression?