Grouped UITableView row animation quirks

If you remove, add and/or move several rows in a UITableView at the same time, then you must enclose all these calls with beginUpdates and endUpdates. Otherwise the result is undetermined.

For example:

[tableView beginUpdates];
[tableView insertRowsAtIndexPaths:newRows 
                    withAnimation:UITableViewRowAnimationTop];
[tableView deleteRowsAtIndexPaths:invalidRows:
                    withAnimation:UITableViewRowAnimationTop];
[tableView endUpdates];