The white dot issue is for an older technology (DLP) and has no bearing on LCD panels.
If it's only one station, the issue is likely with the broadcast.
I just purchasd a 55" led lcd 6900 tv from best buy. While watching the baseball game on Channel 11 WPIX here in new york, we noticed a small white spot approx 1/4" oin size about 10" in and up from the bottom left corner of the tv. At this time we have not seen this with any other channel and it doesn't happen all the time.
I've read 100's of complaints about white spots on samsung TV's.
The geek squad here today to fix other issues where my PS 3 amd most tv channels and movies have the sound and movement of lips or action on TV out of sync using an onkyo sr608 receiver said it's only one station and it's the tv camera positioning. Is this a Samgung issue where in during baseball games at certain times, not all the time I get a white spot?