Awww yeah. You loaded a custom dock image?
I use adw ex, not sure if you can do this with the free version, but here is how its done.
I attached to exact BAMF logo as a jpg. which is needed for adw ex DOCK icon. place the pic in your DCIM folder with all of your other gallery pics (or put into named folder, whatever you want, it just needs to be in the DCIM)
open ADW setting by pressing 'menu' soft button -'more' -'adw settings' - 'themes and preferences' - then select 'main dock' dropdown box and choose 'custom' - 'gallery'... then find the pic and select it. this is the first step in getting it to appear as your dock...
you will need to DL 'ADW.elegant' theme from the market. this is the only theme i could find that has icons that appear completely translucent.
if you already know how to use adw then you already know how to select and choose any icon for any app or shortcut... if you have icons on your dock and want them to stay there but be translucent, then you need to long press the icon, select edit, tap on the pic of the icon, then select ADWTheme Icon Packs, and choose 'ADW.Elegent' (in the second row of icons, just press one of the black ones (its not black its translucent)... Then press OK and your icon will still be on the dock but invisible, leaving only the Bamf ICON dock logo
FYI... the reason I have an all white wallpaper is because the ICON dock has a little bit of white around its edges...
have fun

any questions just ask.... I LOVE ADW ex