Fail to compile examples

Hi there.
I run ghc 7.6.3 and cv-0.3.7.
Some of the examples fail to compile, e.g. channels.hs, Chessboard.hs, Histograms.hs, Hough.hs, surf.hs. Probably some more, i haven't tested them all.
Some compile successful (filters.hs, colorUtils.hs).

Example:

[1 of 1] Compiling Main             ( Hough.hs, Hough.o )

Hough.hs:17:119:
    Couldn't match expected type `Matrix (a0, a0)'
                with actual type `[(Foreign.C.Types.CFloat,
                                    Foreign.C.Types.CFloat)]'
    In the first argument of `toList', namely `hough'
    In the expression: toList hough
    In a stmt of a list comprehension: (y, k) <- toList hough

Hough.hs:18:73:
    Couldn't match expected type `Matrix (Int, Int, Int, Int)'
                with actual type `[(Foreign.C.Types.CInt,
                                    Foreign.C.Types.CInt,
                                    Foreign.C.Types.CInt,
                                    Foreign.C.Types.CInt)]'
    In the first argument of `toList', namely `hough2'
    In the expression: toList hough2
    In a stmt of a list comprehension: (x, y, u, v) <- toList hough2

Hough.hs:19:120:
    Couldn't match expected type `Matrix (a0, a0)'
                with actual type `[(Foreign.C.Types.CFloat,
                                    Foreign.C.Types.CFloat)]'
    In the first argument of `toList', namely `hough3'
    In the expression: toList hough3
    In a stmt of a list comprehension: (y, k) <- toList hough3

The number of not compiling files keeps me wondering if i'm doing something wrong, or are some Examples out of date?