found the problem and workaround.
the problem is in the code between lines 460 in the FindFriendLists:function()
it's hanging on the code where it is trying to get the list of custom friends lists that you have created.
if you manually add the line
right after the other ones and reload your page, you are able to save the people onthe list that you manually added to the script.
so with the above line, everyone in my custom list called "MafiaWars" WILL NOT be removed.
nice thanks a lot Eric :)