Tried turning off home sharing in diff places / combos, but can never get A to show up on the aTV.. The only wireless device in this scenario is the Macbook (C) which is working fine, everything else is wired (aTV = gig, pc B = gig, pc A -= 100 mb).. I tried bypassing the 100 mb switch on that one and went straight into the wall for gigabit- but it didn't have any effect..
Not all of these devices are fixed ip, its about half and half.. I guess I could try changing that and see if anything improves but I don't know why it would..