Overriding banner image in Wix 3.5 Wixlib doesn't work in actual MSI

I a开发者_开发问答m using several articles and other questions in order to override the banner bitmap images for a binary wixlib that I am using in 20+ other installers. This library provides our own custom UI, some custom dialogs, common resources, binaries, custom actions, etc.

Here is the code I am using in the wixlib to override the images:

    <Binary Id="WixUI_Bmp_Banner" SourceFile="Bitmaps\bnnrbmp.bmp/>
    <Binary Id="WixUI_Bmp_Dialog" SourceFile="Bitmaps\dlgbmp.bmp/>

But when I reference my wixlib in my actual MSI project, everything works except for the UI banner image overrides (my custom dialogs fire, process works, common binaries get installed, etc.). Is there something special I need to do in my binary wixlib project to override the UIExtension.wixlib default images in my own binary wixlib?

I saw this question here: Can WixUiBannerBmp be set in a wixlib?, however the answer to that question didn't answer the question, it was directly related to an icon and I'm not sure this guy was using a binary wixlib (re-distributable). My add/remove programs icon embedded in the wixlib already works just fine.

Images are specified via bind-time variables, not Binary elements. Your .wixlib can contain the variable values. The approach used in Can WixUiBannerBmp be set in a wixlib? doesn't use a .wixlib, but otherwise is the same. (A .wixlib is just a collection of .wixobj files.)

The WiX help file documents the variables in "Customizing Built-in WixUI Dialog Sets":

Replacing the default bitmaps

The WixUI dialog library includes default bitmaps for the background of the welcome and completion dialogs and the top banner of the other dialogs. You can replace those bitmaps with your own for product branding purposes. To replace default bitmaps, specify WiX variable values with the file names of your bitmaps, just like when replacing the default license text.

Example:

<WixVariable Id="WixUIBannerBmp" Value="banner.bmp" />
<WixVariable Id="WixUIDialogBmp" Value="dialog.bmp" />