I kind of understand where u r coming from, i have a problem with ppl putting every bad thing that happens to them down to jadoo, HOWEVER, i do believe that jadoo does exist and can be done on people bcos Allah has given people the option to choose to have knowledge of it, and some of these ppl practice it also. But again, it cannot have an effect unless Allah allows it to have an effect.
Of course i would b inclined to say that for someone who is behaving oddly, they would link their odd behaviour with physical evidence of other odd things, like the tawiz etc. But the thing that bothers me is, WHERE did these things appear from, who put them there, and what purpose did these items serve, if not for jadoo? these things are all things that the jadoo practitioner implements.