BSAVEAS strange behavior

I noticed that when I BSAVEAS a block to new name. The resultant block still has the same name in the properties panel but if i LIST the properties it has the newly saved name. Stranger still: If i rename the newly saved block, it still keeps the name of the original block in the properties panel, but if I rename the old block, the newly saved block also gets that name in the properties panel. If i select the newly saved block and choose select similar. It selects the old block as well.
Does anyone have any insight into block and entity naming that would explain this ?