Objective-C - Not freeing memory when a UITableViewController scene appears

I have a simple project using Xcode 4.3.2 focused on iOS 5.1, using storyboards and NavigationController. I just transferred the project to using ARC, and now I notice that the memory is not restored when my UITableViewController scene is called (the back button is pressed). I am sure it worked fine when I was managing the memory myself. I use the "Highlight" function of the Tools tool, and I see that the "Live bytes" continue to increase each time you click on the scene, and then appear. Interface for UITableViewController:

#import <UIKit/UIKit.h>
#import "ASIHTTPRequest.h"

@interface StockListView : UITableViewController <UISearchBarDelegate>
{
    NSMutableArray *tableListArray;         
    IBOutlet UISearchBar *searchBarControl;
}

@property (nonatomic) ASIHTTPRequest *httpDSRequest;

@end

UITableView uses the custom UITableViewCell class defined as follows:

#import <UIKit/UIKit.h>

@interface StockListCell : UITableViewCell

@property (nonatomic) IBOutlet UILabel *lblStockCode;
@property (nonatomic) IBOutlet UILabel *lblDescription;
@property (nonatomic) IBOutlet UILabel *lblQtyInStock;
@property (nonatomic) IBOutlet UILabel *lblQtyFree;

@end

- , , ? - , , ARC?

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, , iOS.