[SOLVED] NSURLConnection crashes after two times

I am use below address to download a mp3 file. I have a uitoolbarbutton and when this button tapped I call downloadandCreatePath and then it make a view that contains my`downloadProgressV' and a UIButton for cancelling the download.

I click download the view appears and download. Download done successfully and also if I cancel, it works fine too.

The problem is that if I do it for second time and then third time. The app crashes on the third time with EXC_BAD_ACCESS message on my appdelegate.

NSURLResponse *urlResponse;
NSMutableData *downloadedMutableData;
NSURLConnection *connectionManager;

- (NSString *) downloadandCreatePath: (int) doaId
{
    @try {

        self.downloadProgressV.progress=0.0;

        self.downloadView.hidden=NO;


        NSString *stringURL = @"http://www.ergmusic.com/mp3-samples/488000/488799.mp3";

        NSURLRequest *urlRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:stringURL]
                                                    cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
                                                timeoutInterval:60.0];

        connectionManager = [[NSURLConnection alloc] initWithRequest:urlRequest delegate:self];

        if (!connectionManager) {
            // Release the receivedData object.
            downloadedMutableData = nil;
            // Inform the user that the connection failed.
        }

    }
    @catch (NSException *exception) {
        NSLog(@"buuuuuuug");
        return @"";
    }
}

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    [downloadedMutableData setLength:0];
    urlResponse = response;
}

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [downloadedMutableData appendData:data];
    self.downloadProgressV.progress = ((100.0/urlResponse.expectedContentLength)*downloadedMutableData.length)/100;
}

- (void)connection:(NSURLConnection *)connection
  didFailWithError:(NSError *)error
{
    connectionManager = nil;
    downloadedMutableData = nil;
}

-(void)connectionDidFinishLoading:(NSURLConnection *)connection {

    self.downloadProgressV.progress=0.0;
    self.downloadView.hidden = YES;
    connectionManager = nil;
    downloadedMutableData = nil;

}

- (IBAction)cancelDownloadTouchUpInside:(id)sender {
    self.downloadView.hidden=YES;
    [connectionManager cancel];
    connectionManager = nil;
    downloadedMutableData = nil;
}

Does any one knows where is my problem?

UPDATE

I try to debug the app with nszombies using below instruction:

http://michalstawarz.pl/2014/02/22/debug-exc_bad_access-nszombie-xcode-5/

but the error do not accourd in this time.

UPDATE

I instanitiate the NSMutableData in my viewdidload method.

Also I try to instantiate it on the first line of downloadandCreatePath but still I see the error.

UPDATE The error occurs after 2 time run and when I want to try initialize the connectionManager. I am wondering why after two time run and in the third try the problem occurs. Why it is not live after first run and in the second try?!!

update

I think below stack trace is better:

    <_NSCallStackArray 0x94ee270>(
0   ???                                 0x097c85cf 0x0 + 159155663,
1   MafatihTebyan                       0x00010cb4 -[DoaShowViewController downloadandCreatePath:] + 404,
2   MafatihTebyan                       0x000114be -[DoaShowViewController DisplayDoaPlayView:] + 94,
3   libobjc.A.dylib                     0x0181f874 -[NSObject performSelector:withObject:withObject:] + 77,
4   UIKit                               0x0057d0c2 -[UIApplication sendAction:to:from:forEvent:] + 108,
5   UIKit                               0x00851c9b -[UIBarButtonItem(UIInternal) _sendAction:withEvent:] + 139,
6   libobjc.A.dylib                     0x0181f874 -[NSObject performSelector:withObject:withObject:] + 77,
7   UIKit                               0x0057d0c2 -[UIApplication sendAction:to:from:forEvent:] + 108,
8   UIKit                               0x0057d04e -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61,
9   UIKit                               0x006750c1 -[UIControl sendAction:to:forEvent:] + 66,
10  UIKit                               0x00675484 -[UIControl _sendActionsForEvents:withEvent:] + 577,
11  UIKit                               0x00674733 -[UIControl touchesEnded:withEvent:] + 641,
12  UIKit                               0x005ba51d -[UIWindow _sendTouchesForEvent:] + 852,
13  UIKit                               0x005bb184 -[UIWindow sendEvent:] + 1232,
14  UIKit                               0x0058ee86 -[UIApplication sendEvent:] + 242,
15  UIKit                               0x0057918f _UIApplicationHandleEventQueue + 11421,
16  CoreFoundation                      0x01a1383f __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15,
17  CoreFoundation                      0x01a131cb __CFRunLoopDoSources0 + 235,
18  CoreFoundation                      0x01a3029e __CFRunLoopRun + 910,
19  CoreFoundation                      0x01a2fac3 CFRunLoopRunSpecific + 467,
20  CoreFoundation                      0x01a2f8db CFRunLoopRunInMode + 123,
21  GraphicsServices                    0x0303b9e2 GSEventRunModal + 192,
22  GraphicsServices                    0x0303b809 GSEventRun + 104,
23  UIKit                               0x0057bd3b UIApplicationMain + 1225,
24  MafatihTebyan                       0x00008a2d main + 141,
25  libdyld.dylib                       0x03c1d725 start + 0,
26  ???                                 0x00000001 0x0 + 1
)

Important UPDATE

I noticed that the codes is not working on iOS 6 even at first call.In iOS 6 It keeps crashing all times.

UPDATE

All samples that I see for NSURLConnection are using viewdidload for creating request file. I am using it in a method and call this method again and again. because the url is changing at each call. May the problem about this?