Cocoa says not KVC compliant

FROM : Milen Dzhumerov
DATE : Wed Jul 02 19:13:53 2008

Hi all,

I've run into a something I find strange. I've got a property declared 
as:

@property(readwrite, assign, nonatomic) CGImageRef image;

And it's implemented as:

-(CGImageRef)image
{
   return mImage;
}

-(void)setImage:(CGImageRef)newImage
{
   if(mImage != newImage)
   {
       CGImageRelease(mImage);
       CGImageRetain(newImage);
       mImage = newImage;
   }
}

When I try to set it using KVC (e.g. [obj setValue:[NSValue 
valueWithPointer:image] forKeyPath:@"image"]), it says [<*ClassName* 
0x133050> setValue:forUndefinedKey:]: this class is not key value 
coding-compliant for the key image.'

Any hints on why the class is not KVC-compliant? I've read the docs 
and it seems to satisfy the bullet points listed (moreover it's even 
declared as @property so the naming of the setters / getters should be 
alright).

Thanks,
M