OpenGL behaving strangely - objective-c

Question

OpenGL is acting very strangely for some reason. In my subclass of NSOpenGLView, I have the following code in the -prepareOpenGL method:
- (void)prepareOpenGL {
GLfloat lightAmbient[] = { 0.5f, 0.5f, 0.5f, 1.0f };
GLfloat lightDiffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f };
GLfloat lightPosition[] = { 0.0f, 0.0f, 2.0f };
quality = 0;
zCoord = -6;
[self loadTextures];
glEnable(GL_LIGHTING);
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glClearColor(0.2f, 0.2f, 0.2f, 0.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glLightfv(GL_LIGHT1, GL_AMBIENT, lightAmbient);
glLightfv(GL_LIGHT1, GL_DIFFUSE, lightDiffuse);
glLightfv(GL_LIGHT1, GL_POSITION, lightPosition);
glEnable(GL_LIGHT1);
gameState = kGameStateRunning;
int i = 0; // HERE ********
[NSTimer scheduledTimerWithTimeInterval:0.03f target:self
selector:#selector(processKeys) userInfo:nil repeats:YES];
// Synchronize buffer swaps with vertical refresh rate
GLint swapInt = 1;
[[self openGLContext] setValues:&swapInt forParameter:NSOpenGLCPSwapInterval];
// Setup and start displayLink
[self setupDisplayLink];
}
I wanted to assign the timer that processes key input to an ivar so that I could invalidate it when the game is paused (and reinstantiate it on resume), however when I did that (as apposed to leaving it at [NSTimer scheduledTimer…), OpenGL doesn't display the cube I draw. When I take it away, it's fine. So i tried just adding a harmless statement, int i = 0; (maked // HERE *******), and that makes the lighting not work! When I take it away, everything is fine, but when I put it back, everything is dark. Can someone come up with a rational explanation for this? Just creating any variable makes it do this, even though there are already several declared.
Thanks.

Answer 1

Very strange, but I found the problem. In this line:
GLfloat lightPosition[] = { 0.0f, 0.0f, 2.0f };
I have only 3 elements instead of 4. I have no idea why it worked when I didn't have int i = 0;, but when I add 0.0f to the array everything works normally.