UITableView reloadData lags wrong offset - ios

Question

I'm making some kind of Facebook timeline similar app when new posts are added at certain offset of UITableView. After adding new posts to dataSource I [self.tableView reloadData] and everything is fine except small lag and sometimes wrong offset (+/- 150 px sometime depending in which direction you are scrolling).
Code:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"PostCell";
PostCell *postCell = (PostCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
// Configure the cell...
Post *post = self.displayPosts[indexPath.row];
[postCell setPost:post];
return postCell;
}
- (void)updatePosts
{
[[APIClient sharedInstance] downloadPostsForPage:_currentPage withSuccessionBlock:^(NSArray *posts) {
NSLog(#"Display new posts!");
[self.displayPosts addObjectsFromArray:posts];
[self.mainTableView performSelectorOnMainThread:#selector(reloadData) withObject:nil waitUntilDone:YES];
_isLoadingMore = NO;
} failureBlock:^(NSError *err) {
// handle error
[self handleError:err];
}];
}
Post Cell:
#interface PostCell ()
#property (weak, nonatomic) IBOutlet PostView *postView;
#property (nonatomic, strong) Post *post;
#end
#implementation PostCell
- (void)setPost:(Post *)newPost
{
self.postView.post = newPost;
}
PostView:
- (void)setPost:(Post *)newPost
{
if (_post != newPost) {
_post = newPost;
}
[self layoutSubviews];
[self refreshContent];
}
- (void)layoutSubviews
{
[super layoutSubviews];
// define title attributes
NSDictionary *attributes = #{
NSForegroundColorAttributeName : [UIColor blackColor],
NSFontAttributeName : [UIFont systemFontOfSize:20.0f]};
CGFloat boundingTitleWidth = self.bounds.size.width - LEFT_TITLE_OFFSET - RIGHT_TITLE_OFFSET;
CGRect titleRect = [_post.title boundingRectWithSize:CGSizeMake(boundingTitleWidth, CGFLOAT_MAX) options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading) attributes:attributes context:nil];
if (self.titleLabel == nil) {
self.titleLabel = [[UILabel alloc] init];
[self addSubview:self.titleLabel];
}
[self.titleLabel setFrame:CGRectMake(LEFT_TITLE_OFFSET, TOP_TITLE_OFFSET, titleRect.size.width, titleRect.size.height)];
[self.titleLabel setNumberOfLines:0];
[self.titleLabel sizeToFit];
// Draw the quarter image.
CGFloat imageY = TOP_TITLE_OFFSET + titleRect.size.height + TOP_IMAGE_OFFSET;
CGPoint point = CGPointMake(LEFT_IMAGE_OFFSET, imageY);
CGSize imageSize = self.post.image.size;
if (self.imageView == nil) {
self.imageView = [[UIImageView alloc] init];
[self addSubview:self.imageView];
}
[self.imageView setFrame:CGRectMake(point.x, point.y, imageSize.width, imageSize.height)];
}
- (void)refreshContent
{
[self.titleLabel setText:_post.title];
[self.imageView setImage:self.post.image];
}
Any help?
Thanks.