You can set x for columns: http://jsfiddle.net/fVrbQ/1/
series: [{
name: 'firefox 3.0',
data: [[0,2]],
stack:0
}, {
name: 'chrome 24.0',
data: [[1,1]],
stack:1
}, {
name: 'ie 9.0',
data: [[2,2]],
stack:2
}, {
name: 'ie 10.0',
data: [[2,1]],
stack:2
}]