Probably Wayfinder is different from Navicore Personal which I'm using on my N800, but I had a similar problem: after updating to OS2008 Navicore Personal didn't work. Instead, it launched the map application which came available with the new OS. I tried uninstalling both the map application and Navicore Personal and then installing the Navicore Personal again, but it still didn't work. Doh! I guess I'm switching back to OS2007 where everything worked just fine.