I'm playing with Minecraft 1.8.1 on a server with Minecraft 1.8.
The default key bounds (Sneak=shift, Run=Ctrl) works great.
But I've rebound those to Sneak=Ctrl and Run=Shift.
And what is not working is that the sneak key on Ctrl does nothing beside make you run off and die cause you thought sneak would help you.
While most of you would not care, I can't play on this parkour server with the default keys.
Why would the server require you to rebind the keys? Pressing Ctrl after rebinding keys caused sneaking as expected, pressing shift caused sprinting.