Digital Underground with Tinfoil Hats,  
Looks like I need a refresher course on #gimp and photo manipulation... #coding
Nowadays I just set the background image with CSS rather than trying to resize my images pixel-perfect:

.header {   background: url('../images/header-image.jpg')  no-repeat; background-size: cover; height: 200px; width: 100%;  }
no-repeat! That's what I forgot!  smh. I bet it'll work now. I already decided on the CSS route but haven't sat down to do it yet. Thanks guys!
Just git pushed it out right quick and it appears to be working. \o/ Thanks y'all so much.