iOS Table View Cell dont draw the first element after scrolling - ios

Question

I create a table View with a CAGradiantLayer background.
Then I created Labels in the TableViewCell and give them Tags.
Now is my problem, that the next cell after scrolling dont appear. It seems like the next cell is overdrawing or don't get the attributes from the Subclass of UITableViewCell. But the cells after that one cell appears. If I remove the bgLayer it works. I don't know why.
This is the subclass of UITableView
- (void)drawRect:(CGRect)rect
{
NSArray *count = [Elements getElements];
CGFloat height = count.count * 44;
CGRect newRect = rect;
CAGradientLayer *bgLayer = [BGLayer getGreyGradient];
newRect.size.height = height;
bgLayer.frame = newRect;
[self.layer insertSublayer:bgLayer atIndex:0];
and this from UITableViewCell
- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
UIView *bg = [[UIView alloc] init];
self.opaque = NO;
self.backgroundColor = [UIColor clearColor];
if(selected)
{
bg.backgroundColor = [UIColor redColor];
[self setBackgroundView:bg];
// cell mit tags von 100 - 106
for(NSInteger i=100; i<107; i++)
{
UILabel *str = (UILabel *)[self viewWithTag:i];
str.textColor = [UIColor whiteColor];
}
}
else
{
bg.backgroundColor = [UIColor clearColor];
[self setBackgroundView:bg];
for(NSInteger i=100; i<107; i++)
{
UILabel *str = (UILabel *)[self viewWithTag:i];
str.textColor = [UIColor blackColor];
}
}
[super setSelected:selected animated:animated];
Thanks for help