Rails 3.2 assets and jQuery_mobile css , issue with jquery image urls

I am testing my first mobile app using Rails 3.2 and jQuery_mobile
running as expected , BUT the app cannot display the images/icons
from jQuery_mobile css…

all urls are defined like that :

background-image: url(images/icons-18-white.png)

and obviously it doesn’t cope with Rails 3.3 asset management …
I am getting ‘no route matches’ errors :

Started GET “/assets/images/icons-18-white.png” for at
2012-08-11 12:13:38 +0200
ActionController::RoutingError (No route matches [GET] “/assets/images/

is there anyway to solve this issue but modifying all urls in the
jQuery_mobile css to be
background-image: url(assets/icons-18-white.png)

thanks for feedback

[SOLVED] I forgot I can move all these images into :
vendor/images/images …
running fine now