I have a webpart that is part of a larger solution, deployed as a WSP using WSPBuilder. I can see the SafeControl entry in the web.config and can see that the assembly has deployed to the GAC. The solution reports as installed OK in Central Admin and the feature is activated at the site collection. When I attempt to add the webpart to a page, I'm getting an error stating that the "Type could not be found or is not registered as safe." I have removed this solution from MOSS and completely re-created the webpart, in case I've messed up GUIDs or something. I'm not sure what to check next. Any thoughts?
This could be a couple of things.
Did you check your ULS logs?
Check that the safe control entry matches your class exactly (an easy way to do this is to use Reflector on your class). Another "gotchas" is if you made your web part class public.