I don't have access to WireShare presently. It sounds like either you are closing the settings window without clicking OK button or you are not pressing the enter button when you wish to add the host.

Or due to the most recent hosts added being at the bottom of the list you have not scrolled down to the bottom of the list of blacklisted hosts. I recall it was far easier to scroll to bottom of the blacklist with LW 4 whereas with WireShare it can take a while depending on how many are in the list.