take a look into your access-logs for a 404-error. then you should see the access-code where tomcat looks for the pics. you'll have to change the links then.
btw., renaming your web-app to ROOT is the worst of all solutions: Since this is a standard-app of tomcat, your client will pretty much likely already have a context named ROOT. cheers greg -- what's puzzlin' you, is the nature of my game