Hi, I have a prblem with my code. I have a viewController and a singleton class. When i call the method readXml and run a for my program update the UITextView. When i call the clearTextView method the program exit with EXC_BAD_ACCESS. The prblem it's the name of the variable position. This is invalid but i don't change anything between the two methods. You have an idea? My code:

#import "PositionIdentifierViewController.h"
#import "WriterXML.h"
#import "ParserXML.h"

#define timeToScan 0.1


@implementation PositionIdentifierViewController



@synthesize accelerometer;

@synthesize actualPosition;

@synthesize actualX;
@synthesize actualY;
@synthesize actualZ;


-(void)updateTextView:(NSString*)nomePosizione
{
    NSString *string = [NSString stringWithFormat:@"%@",nomePosizione];
    textEvent.text = [textEvent.text        stringByAppendingString:@"\n"];
    textEvent.text = [textEvent.text        stringByAppendingString:string];
}


-(IBAction)clearTextEvent{
 textEvent.text = @"";

 //with this for my program exit
 for(int i=0; i<[[sharedController arrayPosition]count]; i++){
  NSLog(@"sononelfor");
  Position *tempPosition = [[Position alloc]init];
  tempPosition = [[sharedController arrayPosition]objectAtIndex:i];
  [self updateTextView:(NSString*)[tempPosition  name]];
 }
}



-(void)readXml{

    if([sharedController readXml]){

        UIAlertView *alert = [[UIAlertView  alloc] initWithTitle:@"Caricamento Posizioni" message:@"Caricamento effettuato con successo" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];
        [alert  show];
        [alert  release];   

        NSString *string = [NSString    stringWithFormat:@"%d", [[sharedController arrayPosition]count]];
        [self   updateTextView:(NSString*)string];

        //with only this the program is ok
        for(int i=0; i<[[sharedController   arrayPosition]count]; i++){
            NSLog(@"sononelfor");
            Position *tempPosition = [[Position alloc]init];
            tempPosition = [[sharedController arrayPosition]objectAtIndex:i];
            [self   updateTextView:(NSString*)[tempPosition     name]];
        }
    }
    else{

        UIAlertView *alert = [[UIAlertView  alloc] initWithTitle:@"Caricamento Posizioni" message:@"Caricamento non riuscito" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];
        [alert  show];
        [alert  release];   
    }

}


// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];

    sharedController = [SingletonController sharedSingletonController];

    actualPosition = [[Position alloc]init];

    self.accelerometer = [UIAccelerometer sharedAccelerometer];
    self.accelerometer.updateInterval = timeToScan;
    self.accelerometer.delegate = self; 

    actualX=0;
    actualY=0;
    actualZ=0;

    [self   readXml];
}

- (void)dealloc {
    [super dealloc];

    [actualPosition dealloc];

    [super dealloc];
}


@end


#import "SingletonController.h"
#import "Position.h"
#import "WriterXML.h"
#import "ParserXML.h"
#define standardSensibility 2
#define timeToScan .1


@implementation SingletonController

@synthesize arrayPosition;
@synthesize arrayMovement;

@synthesize actualPosition;
@synthesize actualMove;

@synthesize stopThread;


+(SingletonController*)sharedSingletonController{

    static SingletonController *sharedSingletonController;

    @synchronized(self) {
        if(!sharedSingletonController){
            sharedSingletonController = [[SingletonController alloc]init];
        }
    }

    return sharedSingletonController;
}


-(BOOL)readXml{

    ParserXML *newParser = [[ParserXML alloc]init];

    if([newParser   startParsing:(NSString*)@"filePosizioni.xml"]){

        [arrayPosition addObjectsFromArray:[newParser arrayPosition]];

        return TRUE;
    }
    else
        return FALSE;
}


-(id)init{
    self = [super init];
    if (self != nil) {
        arrayPosition = [[NSMutableArray alloc]init];
        arrayMovement = [[NSMutableArray alloc]init];

        actualPosition = [[Position alloc]init];
        actualMove = [[Movement alloc]init];

        stopThread = FALSE;
    }
    return self;
}


-(void) dealloc {
    [super dealloc];
}
@end