Gears of War 2 Glitches

- At least 16 glitches have been found in the game
- Most occur during multiplayer
- A patch has been released, but many glitches have not been fixedKotaku: Gears of War 2 The Ultimate Glitch Collection (December 29, 2008)

Gears of War 2 has been plagued by a number of glitches or bugs since its release for the Xbox 360 on November 7, 2008. Many of the glitches are reported to occur in the multiplayer modes of the game. A patch for the game was released on November 28, 2008, but players are still finding glitches throughout the gameplay.Kotaku: Gears of War 2 The Ultimate Glitch Collection (December 29, 2008)
All About Glitches

The term "glitch" comes from the German word, glitschig, which means "slippery," and is usually applied to problems that occur in the computing and electronics industries, including videogames. Glitch is typically a term used by the general public and not by those in the industry. People who work in computing and electronics more often use the term "bug" to describe the problem.
In videogames, specifically, a glitch is often a programming error that results in the game doing something the programmers did not intend. Glitches can take many forms in games, including serious problems like freezing or crashing, as well as minor issues like graphics displaying incorrectly.
In some games, it's possible to exploit glitches in order to advance gameplay or possess an unfair advantage over other players. Most games undergo rigorous testing before release in order to find and fix any glitches in the game, but it's nearly impossible to find every single glitch in the typical timeframe for testing a game.Wikipedia: Glitch