Are you seeing something that looks like sparkles? If so, try to isolate a specific moment where you see them in a specific spot, then rewind and see if you can see them in that spot again.
Some players have issues - it does happen to about 3% of consumer electronics and I have seen this happen very seriously to a HD DVD player, and have heard reports from some Blu-ray players.
Sometimes it's a bad HDMI cable, sometimes it's a bad player.
Sparklies look like white static flashing up on the screen. Grain is a much more obvious and filmlike effect that may be real, or artificial depending on the film.
Sparklikes will also be consistent, regardless of the title you play. Cars (Pixar) is pristine. No grain, no issues at all - damn near flawless, so if you see it there, then odds are good you have sparklies. Try a new HDMI cable (pick up a short one from
www.monoprice.com) and try it out.