Is there a way to stop unity adding icons to my xcode project?

I'm running xcode 5.0.2 and Unity 4.3 and i'm having trouble managing my icons. I want to define the whole set using the asset catalog feature in xcode. But there seems to be two problems:

• Building the unity project results in my xcode project looking for a number of icons in the libraries group. These icons don't exist so the build errors.

• If I use the default asset collection in xcode "images.xcassets" with image sets "AppIcon" and "LaunchImage" then the build breaks the setup of the catalog.

I can work around both of these issues they're just a nuisance and I get the feeling I'm doing something daft!