The applications are generally very similar. If you're using OS2008 you'll have to switch to Wayfinder.

Incidentally, there are a couple of other threads that discuss this but once you load Wayfinder on OS2008 you'll need to download maps. I was never able to get the download to complete but it turns out the Wayfinder maps are identical to the Nav kit maps and you can copy them over from your nav kit CD or SD card. The other threads discuss what to copy and where to copy it.