When a surface of water (lakes on the roads) enters my field of vision grass tufts blow up to their max size (not scaled by distance) and flicker noticeably (around 4 fps, regardless of my current fps).  Grass tufts otherwise seem to function normally i.e. when I turn my character around, and can no longer see the a lake's surface.  Could anyone verify this, or tell me what settings I can change?

Current Graphics Settings:
Color Depth: 32
Anti-Aliasing: 2xQ
Anisotropic Filtering: 8x
Texture Quality: Highest
Shaders: Highest
Enable Grass: √
Enable Weather: √
Enable VBO: √
Loader Cache: √
Background Loading: World
Particles: High

Playing on a MacBook Pro
(Chipset: GeForce 8600M GT)

Edit: And, should I post this as a bug on the BugTracker?  It'd be my first time trying :/