My TV is at about 140 hours and I played GTA 4 for four hours last night. No IR in the slightest.
I have my settings similar to Elway's and it's been fine.
With GTA I turned up in in-game brightness through the game's options to almost full so I could see better in dark scenes... man that game is dark!
Anyhow, no problems whatsoever for me. I also tried out Warhawk and no IR there with the same settings.
I have also heard that the Game Mode doesn't do anything... I think it's probably true lol.
Daedalus_ - sorry mate, but it looks like your menu is totally different then the US's. Picture does = contrast though. We have an "Advanced options" menu that you can adjust black levels, etc., so see if you have something similar to that.
Not sure about the rest of those thnigs

But looking at your bars, your levels are similar to ours.