Halo 3 Message Board  

When I was playing halo (a loooooooooong time ago before halo 2 & 3) I bumped into a bunch of grunts and ran back round the corner to load my rifle. I was late meeting some friends so I left mid game but in a rush and forgot to pause it. I came back and all the grunts were dead. I told a m8 and apparently if you leave the game playing for so long their methane tanks run out!!
Although I doubt you want to wait for several hours staring out the window when a bullet between the eyes is just as good...