Objective-C type not found - objective-c

Question

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];
float color[4];
} Vertex;
- (void)renderFrame:(Frame*)frame;
- (void)drawObjectsInFrame:(Frame*)frame;
- (void)setupVBOsWithVertices:(Vertex*)vertices Indices:(GLubyte*)indices;
- (void)setPhysicsController:(PhysicsApplicationController*)controller;
#end