Yeah, those nvidia drivers can mess a lot of stuff up, mostly just from overwriting the XFree86Config-4 file. I know you checked there already, but humor me for a second; I don't know anything about your system.
In the "Input Device" section for your keyboard, is there a line that says:
Option "Xkblayout" "se"
? That should be the swedish keymap. You might also try "se_SE". As far as the resolution goes, I'd check to make sure that "1280x1024" is listed under all the Display Modes in the "Screen" section.
I have no idea about aterm, sorry.
Anyway, from the problems you're having and the ones I've had too, I'm definitely going to be backing up my XFree86Config-4 file before I install any nvidia drivers again.
