LOL

http://europe.nokia.com/link?cid=EDITORIAL_529078#faq12
12. Will the warranty be void if I update my Nokia device firmware using Nokia Software Updater?

No, it will not.
http://www.nokia.com.hr/link?cid=PLAIN_TEXT_763008#15
15. Hoæe li garancija biti važeæa ako nadogradim softver koristeæi Nokia Software Updater?

Ne, neæe.