I've seen this happen a few times recently, usually on websites with fixed navigation running down the left hand side. They'll have lovely, fluid layouts, which stretch out on wide screens and stack up on smaller devices, but they'll still fall foul of a sneaky break point few people think about. I'm taking about page height. http://enva.to/KULlDa
Source files for the Tuts+ tutorial: Quick Tip: Spare a Thought for Vertical Break Points