HGL SEG fault

import qualified Graphics.UI.GLFW as GLFW
import Graphics.Rendering.OpenGL
import qualified Control.Concurrent as C
import FRP.Elerea.Param
import Control.Monad

main :: IO ()
main = do
    ic <- GLFW.init
    when ic $ do
        m <- GLFW.createWindow 640 480 "ARC-1" Nothing Nothing
        case m of
          (Just win) -> do
              GLFW.makeContextCurrent m
              GLFW.setErrorCallback $ Just (\e s -> putStrLn $ unwords [show e, show s])
              GLFW.setWindowCloseCallback win $ Just (GLFW.destroyWindow)
              clearColor $= Color4 0.0 1.0 1.0 1
              loop win
          Nothing -> return ()
        GLFW.terminate

loop :: GLFW.Window -> IO ()
loop w = do
    --print =<< GLFW.getCursorPos w
    clear [ColorBuffer, DepthBuffer]
    GLFW.swapBuffers w
    C.threadDelay 1000000
    loop w