To reproduce:
private void RadForm3_Shown(object sender, EventArgs e)
{
    Telerik.WinControls.UI.RadWaitingBar waitbar = new Telerik.WinControls.UI.RadWaitingBar();
    pnlCenter.Enabled = false;
    waitbar.AssociatedControl = pnlCenter;
    waitbar.StartWaiting();
}

Workaround:
Do not disable the control while using the waiting bar

This functionality is applicable to the controls that support search functionality like RadRichTextEditor, RadGridView etc.

How to reproduce: check the attached project and  uncomment the commented line in the designer file

To reproduce:
- Set the mode and add ranges from the properties window.
- The ranges are not added to the track bar

Workaround:
- Use the smart tag or add the ranges in code.

How to reproduce: check project and video
Workaround: use a custom RadTrackBar control as per the attached project

To reproduce:
private void radButton1_Click(object sender, EventArgs e)
{
    radTrackBar1.Minimum = -64000;
    radTrackBar1.Maximum = 64000;
}

Case thread with suggestion for workaround: http://www.telerik.com/community/forums/track-bar-takes-5-to-10-minutes-to-initialize