Have you changed the default settings on the FluidSurfaceInfo? Usually the thing should be flapping around so hard as to be unusable... Usually needs a good dose of damping and setting the speed way lower.
erm... only thing I can think immediately is that the real-time updating might not be set to on in your viewports. But that's a stupid goofy thing that I'm sure you checked first off, so I'm not really certain what the thing could be.