So, we've had the Javelin glitch - a bad enough exploit to get people banned for using it. Now Modern Warfare 2 players report they're seeing sped-up players and iced-over surface physics. Update: The problem should be fixed by now.

[Update, 3 p.m.] Via Twitter, Robert Bowling has explained that this was not a glitch but a server hack - "game files being changed by users on modded kits." A playlist update will prevent matchmaking into modded games. "We can only be reactive with playlist updates that prevent it's spread online," Bowling told Kotaku. "However need to rely on our partners to be proactive on prevention of files being changed locally."

[Update, 1 p.m.] A source at Infinity Ward with knowledge of this situation says it will be fixed by the end of this weekend, with no patch necessary. Super-sprint should have been cleared up by late Saturday Pacific time, and the ice physics as of 2 a.m. Sunday (Pacific.) "[The issues] don't die out immediately," the source said, "but should be nearly [gone] 100 percent by this point." The source, not authorized to comment publicly, spoke on condition of anonymity.

One tipster wrote to say he was in a hardcore team deathmatch on Saturday and

"When I entered the game the glitching was really noticeably. Everyone's run speed was jacked way up and you'd slide/float across the ground like you were on ice rather than solid ground. I've talked to other players and its happened to them in separate games as well."

You can see for yourself in that video above. The player tries to demonstrate the ice-slide aspect of this at about 0:45.

There's tons of chatter out there about this, but so far I've only seen it affecting Xbox 360 versions of the game. If you've seen it crop up on other platforms, let us all know in the comments (with a link if you got one.) I've emailed Robert Bowling to see if Infinity Ward has any comment on this. He hasn't tweeted anything since Friday but I'm sure the studio already knows about the problem.

[hat-tip to Enigma Nemesis for the video above.]