Issue with CGContext and iOS5

OQCAppDelegate.m

- (void)applicationDidFinishLaunching:(UIApplication *)application {
    ...
    [self.navigationController.navigationBar setNeedsDisplay];
    ...
}

OQCStyle.m

#import "OQCStyle.h"


void drawLinearGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef  endColor) {
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGFloat locations[] = { 0.0, 1.0 };
    
    NSArray *colors = [NSArray arrayWithObjects:(id)startColor, (id)endColor, nil];
    CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (CFArrayRef) colors, locations);
    
    CGPoint startPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMinY(rect));
    CGPoint endPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect));
    
    CGContextSaveGState(context);
    CGContextAddRect(context, rect);
    CGContextClip(context);
    CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, 0);
    CGContextRestoreGState(context);
    
    CGGradientRelease(gradient);
    CGColorSpaceRelease(colorSpace);
}

void draw1PxStroke(CGContextRef context, CGPoint startPoint, CGPoint endPoint, CGColorRef color) {
    CGContextSaveGState(context);
    CGContextSetLineCap(context, kCGLineCapSquare);
    CGContextSetStrokeColorWithColor(context, color);
    CGContextSetLineWidth(context, 1.0);
    CGContextMoveToPoint(context, startPoint.x + 0.5, startPoint.y + 0.5);
    CGContextAddLineToPoint(context, endPoint.x + 0.5, endPoint.y + 0.5);
    CGContextStrokePath(context);
    CGContextRestoreGState(context);        
}

void drawGlossAndGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef endColor) {
    drawLinearGradient(context, rect, startColor, endColor);
    CGColorRef glossColor1 = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.35].CGColor;
    CGColorRef glossColor2 = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.1].CGColor;
    CGRect topHalf = CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height/2);
    drawLinearGradient(context, topHalf, glossColor1, glossColor2);
}


@implementation UINavigationBar (UINavigationBarCategory)
- (void)drawRect:(CGRect)rect {
    
    CGColorRef lightColor = [UIColor colorWithRed:255.0 green:255.0
                                             blue:255.0 alpha:1.0].CGColor;
    CGColorRef darkColor = [UIColor colorWithRed:196.0/255.0 green:196.0/255.0
                                            blue:196.0/255.0 alpha:1.0].CGColor;
    CGColorRef highlightColor = [UIColor colorWithWhite:0.9 alpha:1.0].CGColor;
    CGColorRef borderColor = [UIColor colorWithRed:163.0/255.0 green:163.0/255.0
                                              blue:163.0/255.0 alpha:1.0].CGColor;
    
    CGContextRef context = UIGraphicsGetCurrentContext();    
    CGRect navBarRect = self.bounds;
    
    CGContextSaveGState(context);
    CGContextSetFillColorWithColor(context, lightColor);
    CGContextFillRect(context, navBarRect);
    CGContextRestoreGState(context);
    
    drawLinearGradient(context, navBarRect, lightColor, darkColor);  
    
    // Add top 1px border
    CGPoint startPoint = CGPointMake(navBarRect.origin.x, navBarRect.origin.y);
    CGPoint endPoint = CGPointMake(navBarRect.origin.x + navBarRect.size.width - 1, navBarRect.origin.y);
    draw1PxStroke(context, startPoint, endPoint, highlightColor);
    
    // Add bottom 1px border (hides separator)
    CGPoint startPoint2 = CGPointMake(navBarRect.origin.x, navBarRect.origin.y + navBarRect.size.height - 1);
    CGPoint endPoint2 = CGPointMake(navBarRect.origin.x + navBarRect.size.width - 1, navBarRect.origin.y + navBarRect.size.height - 1);
    draw1PxStroke(context, startPoint2, endPoint2, borderColor);
    
    if (SYSTEM_VERSION_LESS_THAN(@"5.0"))
        self.tintColor = [OQCStyle orangeColor];
    else {
        self.tintColor = [UIColor colorWithRed:178.0/255.0 green:178.0/255.0
                                          blue:178.0/255.0 alpha:1.0];
//        self.tintColor = [UIColor redColor];
    }
//    [super drawRect:rect];
    
}

@end