WKBW: I'm north of Toronto, about 90 miles away from ABC's transmitter, but it seems to come in best of the 3 stations in that area (NBC/CBS/ABS). Although sometimes it seems that atmospheric conditions put up a complete wall to anything south of Grand Island for me. NBC is the worst of all; I rarely get that with any reliability. ABC has known issues with brief blips on their network feed, and from what I hear it even happens to cable viewers.

WIVB: Something over there has (always had) problems with certain source material - notably the grainy "here's what likely happened" shots during any CSI show. Not sure if that's your issue, but try tuning in 32 (UPN) instead of 39, it's also showing CBS and so far has no difficulties.