History playlist and missing songs

Hi,

I have a problem with my history playlists. If i delete a song from my collection it also delete that song from all the entries in my history playlists. I know deleting it from all my normal playlists is a good idea, but deleting it from my history seems strange! Deleting a song from the collection doesn't mean that I never played it... Rewriting history is never a good idea, so how do I get this fixed?