Objective-C type not found

I'm trying to compile my Objective-C application but it fails saying "Unknown type name 'OpenGLView'". Now I know what this means but the weird thing is I'm convinced I'm importing it just fine.

#import <Foundation/Foundation.h>
#import "OpenGLView.h"
#import "Frame.h"
#import "Mesh2.h"
#import "Vector2.h"
#import "StaticRigidBody.h"
#import "DynamicRigidBody.h"

@interface PhysicsApplicationController : NSObject {
    Frame* frame;
    OpenGLView* view;
}

It fails on line 11 of this sample. You can see I import it on line 2. The thing which I can't get my head around though is the same import works completely fine in this segment.

#import <UIKit/UIKit.h>
#import "OpenGLView.h"

@interface PhysicsAppDelegate : UIResponder <UIApplicationDelegate> {
    OpenGLView* _glView;
}

Both source files for the two segments are in the same directory. I have no idea what is going on.

[EDIT] Content of OpenGLView.h

#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#include <OpenGLES/ES2/gl.h>
#include <OpenGLES/ES2/glext.h>
#import "PhysicsApplicationController.h"


@interface OpenGLView : UIView {
    CAEAGLLayer* _eaglLayer;
    EAGLContext* _context;
    GLuint _colorRenderBuffer;
    GLuint _positionSlot;
    GLuint _colorSlot;
    PhysicsApplicationController* _physicsController;
}

typedef struct {
    float position[3];
开发者_JAVA技巧    float color[4];
} Vertex;

- (void)renderFrame:(Frame*)frame;
- (void)drawObjectsInFrame:(Frame*)frame;
- (void)setupVBOsWithVertices:(Vertex*)vertices Indices:(GLubyte*)indices;
- (void)setPhysicsController:(PhysicsApplicationController*)controller;

@end