iAd Banner view position too high on screen

[crunkstar]

My app contains an iAd banner that I am trying to position lower on the screen where the Tab Bar is located.

I successsfully removed the tab bar and now need the iAd banner to move down to cover the tab bar position.

But the iAd banner is moving as if the Tab Bar is still there. I've tried adding the following line to the code and changing the Y position number (50) to larger and smaller numbers to change the Y position but it doesn't move.

bannerView.frame = CGRectOffset(bannerView.frame, 0, 50);

My code is from the WWDC presentation Integrating Ads with iAd.

But I'll include the part which I think is relevant. I think this is the part I need to amend but I'm not sure. I'm still new to programming.
Any help is welcome.

- (void)moveBannerViewOffscreen
{
	// Make the table view take up the void left by the banner.
	CGRect originalTableFrame = self.tableView.frame;
	CGFloat newTableHeight = self.view.frame.size.height;
	CGRect newTableFrame = originalTableFrame;
	newTableFrame.size.height = newTableHeight;
	
	// Position the banner below the table view (offscreen).
	CGRect newBannerFrame = self.bannerView.frame;
	newBannerFrame.origin.y = newTableHeight;
	
	self.tableView.frame = newTableFrame;
	self.bannerView.frame = newBannerFrame;
	
}

- (void)moveBannerViewOnscreen
{
	CGRect newBannerFrame = self.bannerView.frame;
	newBannerFrame.origin.y = self.view.frame.size.height - newBannerFrame.size.height;
	
	CGRect originalTableFrame = self.tableView.frame;
	CGFloat newTableHeight = self.view.frame.size.height - newBannerFrame.size.height;
	CGRect newTableFrame = originalTableFrame;
	newTableFrame.size.height = newTableHeight; 
	
	[UIView beginAnimations:@"BannerViewIntro" context:NULL];
	self.tableView.frame = newTableFrame;
	self.bannerView.frame = newBannerFrame;
	[UIView commitAnimations];
	
}