title: UITableView some separator line missing
body: <p>I am using code to build a uitableview like this:</p>
  <pre><code>UITableView *tableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 290, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height - 290)]; 
  tableView.delegate = self;
  tableView.dataSource = self;
  [tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@&quot;settingtabcell&quot;];
  </code></pre>
  <p>And the dataresource and viewdelegate</p>
  <pre><code>- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
      static NSString *CellIdentifier = @&quot;settingtabcell&quot;;
      UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
      
      if (cell == nil) {
          cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
      }else{
          for(UIView *subview in cell.subviews){
              [subview removeFromSuperview];
          }
      }
      UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(70, 0, [UIScreen mainScreen].bounds.size.width - 20, 90)];
      UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(10, 30, 32, 32)];
      
      switch (indexPath.row) {
          case 0:
              label.text = @&quot;Copyright information&quot;;
              imageView.image = [UIImage imageNamed:@&quot;copyright.png&quot;];
              break;
          case 1:
              label.text = @&quot;Clear cache&quot;;
              imageView.image = [UIImage imageNamed:@&quot;clearcache.png&quot;];
              break;
          case 2:
              label.text = @&quot;Feedback&quot;;
              imageView.image = [UIImage imageNamed:@&quot;feedback.png&quot;];
              break;
          case 3:
              label.text = @&quot;About us&quot;;
              imageView.image = [UIImage imageNamed:@&quot;about.png&quot;];
              
          default:
              break;
      }
      cell.selectionStyle = UITableViewCellSelectionStyleNone;
      [cell addSubview:imageView];
      [cell addSubview:label];
      return cell;
  }
  
  -(NSInteger) tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
      return 4;
  }
  
  -(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
      return 90;
  }
  </code></pre>
  <p>The thing is some separator line is missing and some are not, this really confusing me.</p>
  <p><a href="https://i.stack.imgur.com/8gEOO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8gEOO.png" alt="enter image description here" /></a></p>
  <p>So what may have caused this problem?</p>
  <h2>EDIT</h2>
  <p>To those who may concern, this screenshot is not on a simulator but was captured on an ihpone device.</p>
  <p>And the line was originally showed except that after scrolling down and bouncing back, the line was missing.</p>