This is a bug for sure.
In the ftp if you have a bunch of files, you select one (to give focus to the control) and then press a letter on the keyboard (lets say 'M') to go to the first instance of a file or folder starting with letter 'M'. However, the problem is that the first directory selected is the one before the first directory starting with 'M'. As you keep pressing 'M' you never hit the last file/folder starting with 'M', instead you hit the second last one.
Anyways, the bottom line is that the index is out of range/- 1.
Not a big deal tho -- thought I would mention it.