omega, there is something odd here because the steps you are following seem correct to me.
Could you post a file with the log created by the installation? You know, the thing things it writes while it is installing such as "file x replaced succesfully" and so.
I supose you are already doing it, but just in case, did you extracted the original char.lgp?
By the way, crimsondante my idea is to redo all the field models left. But let's be serious: only one person cannot finish redoing every single character contained in char.lgp. Well, maybe one can but, for sure, not me. I know that sooner or latter I'll get bored. But that's not bad. I'm not a especially brilliant modder. I'm completly sure that there's a lot of people out there who can do a better job (Reunion, for example). They just need to try it. Rebuilding a field model is not very different from playing Lego. But you know, Lego isn't allways that simple...