[Fisneaky]

how do you convert them to tga? still having trouble with that

Simplest way I know of (as stated above)

Backup the "background.tga" (ie. copy into a folder named "-backup"

open "background.tga" in your graphics editor

Copy your new .jpg, .bmp or whatever and paste it over the "background.tga" merge/flatten and save.

Gimp, PSP or Photoshop should all handle this OK.