It happened recently that I downloaded some files of a torrent
and after it was finished I noticed that not all the files
selected were 100% completed. Then if I unchecked, and checked
again one of this uncompleted files, they completed downloading.

I tried again with this small torrent if you want to try
From Isohunt, go to this search page and download the torrent of size 6.39 MB

http://www.isohunt.com/torrents/?ihq=ad ... rogramming

I selected to download this files:
apA
ch01
ch07
ch11
index
toc

But only the two last ones completes.

I'm on revision 601002

I can confirm it on same revision. v2.0.3 is clean of it.

Thanks for reporting!

Weird, I've experienced this last night too. I was kinda hoping it was a one-time bug...

I don't know exactly in which revision this problem started. But I think that the bug was introduced after the modification on how ktorrent behaves when a file is unchecked, and not deleted.