UITableView row delete animation flickers on iOS 7

My app has a UITableView containing variable-height cells with transparent backgrounds. When building against the iOS 7 SDK there's a problem with the row deletion animation:

Note the flickering of some cells, e.g. rows 15, 17, 21 and 23. This behavior was not observed on iOS <= 6.

If I do any of these things the problem goes away (none of which I'm yet prepared to do):

• Always creating new cells instead of dequeueing reusable cells
• Giving cells non-transparent backgrounds
• Giving all rows the same height

Nothing else I've tried helps. Is there some secret sauce required on iOS 7 to get smooth row deletion animations?

Here's the smallest test case I can distill the problem to [C#/Xamarin]:

public class MainViewController : UITableViewController {

    public MainViewController() {
        this.TableView.Source = new TableSource(this.TableView, 50);
    }

    public override void ViewDidAppear(bool animated) {
        base.ViewDidAppear(animated);
        NSTimer.CreateRepeatingScheduledTimer(0.5f, ((TableSource) this.TableView.Source).DeleteFirstRow);
    }
}

public class TableSource : UITableViewSource {

    private UITableView tableView;
    private List<RowInfo> activeRows;

    public TableSource(UITableView tableView, int numRows) {

        this.tableView = tableView;

        this.activeRows = new List<RowInfo>();
        for (int i=1; i<=numRows; i++) {
            this.activeRows.Add(new RowInfo(i));
        }
    }

    public void DeleteFirstRow() {

        if (this.activeRows.Count == 0) return;

        this.activeRows.RemoveAt(0);

        this.tableView.BeginUpdates();
        this.tableView.DeleteRows(new NSIndexPath[] { NSIndexPath.FromRowSection(0, 0) }, UITableViewRowAnimation.Right);
        this.tableView.EndUpdates();
    }

    public override int RowsInSection(UITableView tableview, int section) {
        return this.activeRows.Count;
    }

    public override float GetHeightForRow(UITableView tableView, NSIndexPath indexPath) {
        return this.activeRows[indexPath.Row].Height;
    }

    public override UITableViewCell GetCell(UITableView tableView, NSIndexPath indexPath) {

        const string CellID = "Cell";

        UITableViewCell cell = tableView.DequeueReusableCell(CellID);
        if (cell == null) {
            cell = new UITableViewCell(UITableViewCellStyle.Default, CellID);
        }
        cell.TextLabel.Text = this.activeRows[indexPath.Row].Text;

        return cell;
    }

    public override void WillDisplay(UITableView tableView, UITableViewCell cell, NSIndexPath indexPath) {
        cell.BackgroundColor = UIColor.Clear;
    }

    private class RowInfo {

        public RowInfo(int index) {
            Random random = new Random(index);
            this.Height = random.Next(20, 80);
            this.Text = "Row " + index + " has height " + this.Height;
        }

        public float Height;
        public string Text;
    }
}