When you delete file #60 in Windows Explorer, you can then use Cursor up/down to quickly move to file #64. (Same behavior in other programs.)
When you delete file #60 in FileZilla, you'll notice that you were pushed back up to file #1 when you use Cursor up/down.
I'm using the keyboard a lot and this has annoyed me for quite a while now, would be great to get this fixed!
