When I first got Alpha Protocol, i'd heard a lot about the conversation system, but hadn't actually seen any screenshots/video of it.
So I installed it, booted it up, and started playing - and when the first conversation came up, the choices were blank squares with no reference to what would be said or what I had to do to trigger each option. I thought the conversation system was over-rated and quit after a while, deleting my progress, uninstalling etc.
A week or so later I realized it was a video card driver bug, and that installing new drivers enabled me to see the options.