Hi, my 13" cMBP seems to have an issue with either the thunderbolt port to with the thunderbolt to VGA adapter. At very rare instances (once a week or so) the picture being displayed on the external monitor will spazz out. Sometimes it seems like there is a timing delay in the hsync and vsync signals and other times the behavior is totally undefined and there is weird gray stuff everywhere. I have apple care. Will apple give me a logic board swap if I take it in or will they test and say that their test showed nothing and that nothing is wrong?