Files for custom theme are not generated - default theme is downloaded instead

I've been attempting to create a custom theme on the current version of the Themeroller. The live preview in the Themeroller interface is accurate.

When I attempt to download the custom theme by clicking the Download Theme button, the zip file I receive doesn't contain any of the specified colors or custom icon PNGs. It appears to be the default theme that is displayed in the Themeroller for a new visitor.

Here is the URL that is passed to the Themeroller download configuration page:

http://jqueryui.com/download/?themeParams=%3FffDefault%3D%2522Helvetica+Neue%2522%252CArial%252CHelvetica%252Csans-serif%26fwDefault%3Dnormal%26fsDefault%3D1.1em%26cornerRadius%3D4px%26bgColorHeader%3DECF4DB%26bgTextureHeader%3D07_diagonals_medium.png%26bgImgOpacityHeader%3D50%26borderColorHeader%3DC8CCBE%26fcHeader%3D222222%26iconColorHeader%3D527320%26bgColorContent%3Dffffff%26bgTextureContent%3D12_gloss_wave.png%26bgImgOpacityContent%3D100%26borderColorContent%3DC8CCBE%26fcContent%3D222222%26iconColorContent%3D527320%26bgColorDefault%3DEBEBEB%26bgTextureDefault%3D02_glass.png%26bgImgOpacityDefault%3D90%26borderColorDefault%3Dd3d3d3%26fcDefault%3D555555%26iconColorDefault%3D527320%26bgColorHover%3DECF4DB%26bgTextureHover%3D02_glass.png%26bgImgOpacityHover%3D100%26borderColorHover%3D76b125%26fcHover%3D527320%26iconColorHover%3D76b125%26bgColorActive%3D76b125%26bgTextureActive%3D02_glass.png%26bgImgOpacityActive%3D35%26borderColorActive%3DC8CCBE%26fcActive%3Dffffff%26iconColorActive%3Dffffff%26bgColorHighlight%3DFCF7D9%26bgTextureHighlight%3D02_glass.png%26bgImgOpacityHighlight%3D55%26borderColorHighlight%3DF9E455%26fcHighlight%3D363636%26iconColorHighlight%3D76b125%26bgColorError%3Dfef1ec%26bgTextureError%3D05_inset_soft.png%26bgImgOpacityError%3D95%26borderColorError%3Dcd0a0a%26fcError%3Dcd0a0a%26iconColorError%3Dcd0a0a%26bgColorOverlay%3Daaaaaa%26bgTextureOverlay%3D01_flat.png%26bgImgOpacityOverlay%3D0%26opacityOverlay%3D30%26bgColorShadow%3Daaaaaa%26bgTextureShadow%3D01_flat.png%26bgImgOpacityShadow%3D0%26opacityShadow%3D30%26thicknessShadow%3D8px%26offsetTopShadow%3D-8px%26offsetLeftShadow%3D-8px%26cornerRadiusShadow%3D8px