It sounds to me Like your having some fungus problems..

You have to be verry careful when removing the deseased Part Of the Bud Because the Spaws of the fungus can be easily spread to other Parts of the Plant..
Alot Of people will remove the entire infected Branch But I have Carefully snipped chunks of infected bud off and it didnt spread or return...
I could be way wrong but thats what it sounds like to me...