To reproduce use the following configuration for the DateTimePicker:
public Form1()
{
    InitializeComponent();
    DateTime start = DateTime.Parse("2012/7/1 00:00:00");
    this.RadDateTimePicker1.ShowUpDown = true;
  
    this.RadDateTimePicker1.Format = DateTimePickerFormat.Custom;
    this.RadDateTimePicker1.DateTimePickerElement.ShowCurrentTime = false;
    this.RadDateTimePicker1.MinDate = start;
    this.RadDateTimePicker1.DateTimePickerElement.CustomFormat = "HH:mm";
    this.RadDateTimePicker1.MaxDate = start + TimeSpan.FromMinutes(1440);
    this.RadDateTimePicker1.Value = start +TimeSpan.FromMinutes(1);
    this.RadDateTimePicker1.Enter += new EventHandler(this.ConfigStartDelayTime_Enter);        
}

void ConfigStartDelayTime_Enter(object sender, EventArgs e)
{
    RadMaskedEditBoxElement element = this.RadDateTimePicker1.DateTimePickerElement.TextBoxElement.TextBoxItem.Parent as RadMaskedEditBoxElement;
    MaskDateTimeProvider provider = element.Provider as MaskDateTimeProvider;
    provider.SelectLastItem();
}

Resolution: 
TextBlockElement was removed from EditUI elements, since it is a dynamically added. 

Current behavior:
With decimal places = 2
2.225 is round to 2.22
the proper behavior would be 2.225 to be round to 2.23

IMPROVE. RadSpellChecker - add ability to modify the €œThe spelling check is completed€ text in the message box.

 The default directory is not set correctly when the dialog is SaveFileDialog.

RadMaskEditBox - Wrong cursor placement after typing decimal separator (it goes to the last position) when you change Decimal symbols for Currency as ";"

Workaround:
            this.radMaskedEditBox2.KeyPress += new KeyPressEventHandler(radMaskedEditBox2_KeyPress);
            this.radMaskedEditBox2.KeyUp += new KeyEventHandler(radMaskedEditBox2_KeyUp);
        }

        void radMaskedEditBox2_KeyPress(object sender, KeyPressEventArgs e)
        {
            string separtor = Thread.CurrentThread.CurrentCulture.NumberFormat.CurrencyDecimalSeparator;

            if (e.KeyChar.ToString() == separtor)
            {
                e.Handled = true;
            }
        }

        void radMaskedEditBox2_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.KeyValue == 186)
            {
                RadMaskedEditBoxElement radMaskedEditBoxElement = sender as RadMaskedEditBoxElement;
                int index = radMaskedEditBoxElement.TextBoxItem.Text.IndexOf(';');
                radMaskedEditBoxElement.TextBoxItem.SelectionStart = index + 1;
            }
        }

If you set MaskType to Standard and Mask to  ">LLL_LLL_LLL"   and set the TextMaskFormat property to ExcludePromptAndLiterals, the result value property will be an empty string.

To reproduce: if (e.KeyData == Keys.Back) { radDateTimePicker1.SetToNullValue(); e.Handled = true; } 

Workaround: void radDateTimePicker1_KeyUp(object sender, KeyEventArgs e) { if (e.KeyData == Keys.Back) { radDateTimePicker1.SetToNullValue(); } }

Resolution: 
Users should handle also KeyPress event (and KeyDown event) because the keys.Back is processed on KeyPress  :

         void radDateTimePicker1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == '\b')
            {
                this.radDateTimePicker1.SetToNullValue();
                e.Handled = true;
            }
        }

To reproduce:
- Set the ShowCheckBox property to true and Checked property to false at design-time.
- When the application is started the checkbox is checked.

Workaround:
- Set the state in code:
 radDateTimePicker1.Checked = false;

To reproduce: use the following code:

this.radSpinEditor1.ScreenTipNeeded += screenTipNeeded;

 private void screenTipNeeded(object sender, Telerik.WinControls.ScreenTipNeededEventArgs e)
 {
     Console.WriteLine(e.Item);
     RadOffice2007ScreenTipElement screenTip = e.Item.ScreenTip as RadOffice2007ScreenTipElement;
     if (screenTip == null)
     {
         e.Item.ScreenTip = new RadOffice2007ScreenTipElement();
         screenTip = e.Item.ScreenTip as RadOffice2007ScreenTipElement;
     }
     screenTip.CaptionLabel.Text = "Title of tooltip";
     screenTip.MainTextLabel.Text = "Text of tooltip";
 }


Workaround:

this.radSpinEditor1.SpinElement.TextBoxItem.HostedControl.MouseLeave += radSpinEditor1_MouseLeave;

 private void radSpinEditor1_MouseLeave(object sender, EventArgs e)
 {
     if (this.radSpinEditor1.SpinElement.TextBoxItem.ScreenTip != null)
     {
         this.radSpinEditor1.ElementTree.ComponentTreeHandler.Behavior.HideScreenTip();
     }
 }

The last caret position in RadTextBoxControl is not aligned to the end of the text due to wrong text measurement.

On Win XP machine add RadTextBoxControl (Multiline=true) and start typing a very long text with no blank space between letters. As a result the caret is taken away from the last letter and if you use left arrow to return it back, the caret is positioned in the middle of the letter.

To reproduce:
- Add two RadTextBoxControls to a blank form.
- Double click the one that does not contain the focus with the right mouse button.

Workaround:

radTextBoxControl1.CaretIndex = 0;

1. limitation of the time that can be chosen (e.g. 8 AM to 5 PM)
2. set the interval of increasing and decreasing the Minutes part to 30 instead of 1

NO WORKAROUND

Resolution: 
In release Q2 2014 we are introducing logic that allow to set time range by MinValue and MaxValue properties of RadTimePicker. To set the interval of increasing and decreasing of the minute’s part you can use the MinutesStep property of the MaskDateTimeProvider. 

For example for RadTimePicker:
(this.radTimePicker1.TimePickerElement.MaskedEditBox.Provider as MaskDateTimeProvider).MinutesStep = 30;

For example for RadDateTimePicker:
RadMaskedEditBoxElement mask = (RadMaskedEditBoxElement)this.radDateTimePicker1.DateTimePickerElement.TextBoxElement;
MaskDateTimeProvider provider = mask.Provider as MaskDateTimeProvider;
provider.MinutesStep = 30;

When you have a GridViewDateTimeColumn in the RadGridView and enter in edit mode, you are allowed to clear the current date (set it to null) pressing the Clear button in the popup calendar. However, this functionality is not available in the RadDateTimePicker control.

Workaround:

 public Form1()
 {
     InitializeComponent();
     this.radDateTimePicker1.NullText = "Empty";

     RadDateTimePickerCalendar calendarBehavior = this.radDateTimePicker1.DateTimePickerElement.GetCurrentBehavior() as RadDateTimePickerCalendar;
     calendarBehavior.Calendar.ShowFooter = true;
     calendarBehavior.Calendar.ClearButton.Click += ClearButton_Click;
 }

 private void ClearButton_Click(object sender, EventArgs e)
 {
     this.radDateTimePicker1.DateTimePickerElement.SetToNullValue();
 }

TabStop property cannot be changed and saved in design time - it is not serialized.

It seems that there are differences between Windows XP Korean and the English distributions which cause the OK and Cancel buttons of RadColorDialog to become hidden from view. RadColorDialog should be optimized to support both Windows distributions.

ADD. RadSpellChecker - add ability to disable the "Spell checking complete" message box.

RadTextBox does not serialize its Size if it has been added into FlowLayoutPanel, and in run time it has incorrect size.