. . I did some research in the forum and around the web and just figured out that the "finalize" proccess is actually just a simple copy of certificates that are needed for the phone to work. I used DaVinci to reflash it (this time with w800 firmware) and XS++ tofinalize it correctly.
. . I have a CID36 Red k750i, now with the R1BC002 firmware (America 2 CDA).

. . My phone if fully working and now I just need to learn how to make my songs to appear in that "fancy viewing" with the Artist/Album filter (by this time I can only find them by creating a playlist, but it's so "straightbackward" :P).

. . Thanks everybody who helped. I'm looking forward for next month, when I'll be able to download all those mods in the download section...