Re-using waypoint names

I've created a track with many waypoints. When I finished, I decided that my track had too many waypoints, so I deleted many of them from the waypoints list in the left hand column of the BC display. That done, I wanted to add a few waypoints, but when I try to add waypoints using the same name as some of those that I deleted, I get a pop message saying that the name is invalid. Is BC storing/caching the names somewhere and keeping them even when I delete them from the track? Is there a way to "permanently" delete them so that I can reuse the waypoint names?