I'm not entirely clear on what exactly is being charged for with Limewire Pro. Is it the download and support service that's being charged for? Does LW claim that Basic is derivitive of Pro and not the other way around?

If LW charges $18.99 for the service of downloading LWPro for six months, according to the GPL they're distributing it and therefore are required to permanently provide the source, yes? Is re-registration only for folks who want binaries, or is LW in flagarant violation of the GPL?