Hey Ash,
Editing loadscreens is easy, if you have adobe photoshop, open up the loadscreen, cut out the bar in the middle, put whatever you want as a backround, then put the bar back in the exact same place. Make sure it's saved in Targa as tga.
That's strange your getting ctds! I did a loadscreen for AWI, I need to fix the title, if you want to check it out- the backround comes from a painting by Thomas Cole.
I am, sir, your most humble and obedient servant,
Justin