nsurl to uimageview does not show after parsing json array - ios

Question

Well in my .m file I am doing the following:
I am fetching data over the web and store them in an NSMutable array by parsing json array. These data are images urls (images are on my server) and then I want to set them on my custom cell. each cell has 2 imageviews.
I am parsing the data correctly.
i do store them correctly.
I can see their values printed out and If i open them in a browser they are correct values.
If in my cell place static images from my resources I can see them.
But If i try to set them from the url I do not see anything.
here is my code:
For fetching data:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"connectionDidFinishLoading");
NSLog(#"Succeeded! Received %d bytes of data",[self.responseData length]);
// convert to JSON
NSError *myError = nil;
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&myError];
images_url= [NSMutableArray new];
for (NSDictionary *alert in json ){
NSString* image = [alert objectForKey:#"image"];
[images_url addObject:image];
}
[self.myTable reloadData];
}
where myTable is my synthesized TableView.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
int i=[images_url count]/2;
return i;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier=#"ListTableCell";
//this is the identifier of the custom cell
ListsCell *cell = (ListsCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"ListsCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
/*NSString *url_left=[images_url objectAtIndex:(indexPath.row*2)];
NSLog(#"Left url is:%#",url_left);
NSString *url_right=[images_url objectAtIndex:(indexPath.row*2+1)];
NSLog(#"Right url is:%#",url_right);*/ THEY ARE PRINTED HERE
NSURL *url_left=[NSURL URLWithString:[images_url objectAtIndex:(indexPath.row*2)]];
cell.Left.image=[UIImage imageWithData:[NSData dataWithContentsOfURL:url_left]];
NSURL *url_right=[NSURL URLWithString:[images_url objectAtIndex:(indexPath.row*2+1)]];
return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 81;
}
If I remove the reload data, then I do bot see their values and not the correct number of lines, so it is necessary.
So can anyone find out what is wrong in here?