Our application used to have jquery-ui as a vendor component, downloaded via Bower.
So all files were under /vendor/assets/components/jquery-ui
When a component was called we were having images routing issues as:
ActionController::RoutingError (No route matches [GET] "/assets/images/ui-bg_flat_75_ffffff_40x100.png")
After some stackoverflow search I went through some messages suggesting using jquery-ui-rails gem
So now, all assets are served through Asset Pipeline and routed correctly!