I'm not sure, but I thought LDView is only downloading parts from the server, if the requested part couldn't be found in any ldraw folder.
I hope you divided your libraries in an official and unofficial part. So you just need to delete the files, which needs to be reloaded, in the unofficial folder.
/Max
I hope you divided your libraries in an official and unofficial part. So you just need to delete the files, which needs to be reloaded, in the unofficial folder.
/Max