Splotchy Skybox Texture

[Jedi_Mediator]

Okay, I thought I knew how to fix this issue, but apparently not. My skybox textures are appearing splotchy and grainy in-game. Here is one of the .jpg files used:

https://drive.google.com/open?id=0B5h3mw7Vh5k4c2NGUC12bXNHRU0

As you can see, it's not the most perfect quality to begin with, but it's adequate for my needs. However, here is how it turns out in-game:

https://drive.google.com/open?id=0B5h3mw7Vh5k4cy0yZ2dQd3E3a0U

Note that this only occurs when I use my skybox images on a skybox. When I stretch a single panoramic skydome image over the map (also using a .jpg file), it looks just fine in-game:

https://drive.google.com/open?id=0B5h3mw7Vh5k4WVdVVkNjbzlWWE0

Here is the shader I'm using for the skybox:

//SKYBOX (splotchy)
textures/skies/hazard1_sky
{
    qer_editorimage textures/skies/sky.tga
    skyparms textures/hazard/hazard 1024 -
    q3map_sunExt 1 0.57 0 350 -128 70 2 16
    q3map_lightmapFilterRadius 0 160
    surfaceparm  sky
    surfaceparm  noimpact
    surfaceparm  nolightmap
    surfaceparm  nodlight
    surfaceparm nomarks
    notc
    nopicmip
    nomipmaps
} 

//SKYDOME (looks normal)
textures/hazard/skydome
{
    q3map_nolightmap
    notc
    nopicmip
    nomipmaps    
    {
        map textures/hazard/skydome    
    }
}