To reproduce:
- Set RadForm.FormBorderStyle to FixedDialog
- Set some Icon to the form 
- Run and the icon is not visible

With the standard form, the icon is visible.

Workaround: use FormBorderStyle = FixedSingle

Create a custom theme starting from Aqua theme. Change the Font for RadLabelElement-TextPrimitive to "Microsoft Sans Serif, 10pt". Save the theme and apply it to the entire application. Show several times a RadMessageBox with long text. The first time the RadMessageBox is sized correcly to its content. Each next showing, cuts off the text.

Workaround:  the possible workaround that I can suggest is to dispose the RadMessageBox instance after showing it:

Private Sub RadButton1_Click(sender As Object, e As EventArgs) Handles RadButton1.Click
    RadMessageBox.Show(Me, "If you have some veeeeery long sample text, the messagebox " & _
                       "should be resized according to its content.", "Caption", MessageBoxButtons.OK, My.Resources.image)
    RadMessageBox.Instance.Dispose()
End Sub

Add the ability to show the control where the IWin32Window owner has different handle.

When the form border style is set to none the form still has minimum width.

To reproduce:

public Form1()
{
    InitializeComponent();

    RadMessageBox.Instance.AutoSize = true;
}

private void radButton1_Click(object sender, EventArgs e)
{
    string msg = string.Format("Test", (sender as RadButton).Name);
    RadMessageBox.Show(msg, "Error");
}

Note that the size of  RadMessageBox is adjusted automatically to display the whole content. Hence, it is not necessary to set the RadMessageBox.Instance.AutoSize property to true.

If you have an MDI form with controls anchored to bottom-left, and if the form is shown the following way:

Form form = new ChildForm()
form.MdiParent = this;
form.Show();

private void ChildForm_Load(object sender, EventArgs e)
{
         this.ThemeName = "Office2007Black";
}

the anchored controls will be misplaced.

WORKAROUND:

either set the parent after show:
Form form = new ChildForm()
form.Show();
form.MdiParent = this;

or do not use the Load event to apply theme - use the constructor or the Shown event:

public ChildForm()
{ 
         InitializeComponent();
         this.ThemeName = "Office2007Black";
}

To reproduce: use the following code snippet:

public Form1()
{
    InitializeComponent();

    this.radDropDownList1.SelectedIndexChanged+=radDropDownList1_SelectedIndexChanged;
    this.radDropDownList1.Items.Add("TelerikMetro");
    this.radDropDownList1.Items.Add("Windows8");
    this.radDropDownList1.Items.Add("VisualStudio2012Dark");

    this.radDropDownList1.SelectedIndex = 1;

    this.SizeChanged+=Form1_SizeChanged;
}

private void radDropDownList1_SelectedIndexChanged(object sender, Telerik.WinControls.UI.Data.PositionChangedEventArgs e)
{
    ThemeResolutionService.ApplicationThemeName = this.radDropDownList1.Text;
}

1. Use two monitors and decrease the screen resolution to the main monitor.
2. Run the application from the first monitor and move the form to the second monitor.
3. Resize the form on a way to increase the form's height to be greater than the height of the screen resolution of the main monitor.
4. Change the theme. You will notice that that form is resized.

Workaround:

public Form1()
{
    InitializeComponent();

    this.radDropDownList1.SelectedIndexChanged += radDropDownList1_SelectedIndexChanged;
    this.radDropDownList1.Items.Add("TelerikMetro");
    this.radDropDownList1.Items.Add("Windows8");
    this.radDropDownList1.Items.Add("VisualStudio2012Dark");

    this.radDropDownList1.SelectedIndex = 1;

    this.SizeChanged += Form1_SizeChanged;
}

private void Form1_SizeChanged(object sender, EventArgs e)
{
    if (fSize != Size.Empty)
    {
        this.SizeChanged-= Form1_SizeChanged;
        this.Size = fSize;
        
        this.SizeChanged += Form1_SizeChanged;
    }
}

Size fSize = Size.Empty;

private void radDropDownList1_SelectedIndexChanged(object sender, Telerik.WinControls.UI.Data.PositionChangedEventArgs e)
{
    fSize = this.Size;
    ThemeResolutionService.ApplicationThemeName = this.radDropDownList1.Text;
    fSize=Size.Empty;
}

To reproduce:
- Add RadMenu to a panel which is docked to the top.
- Add an MDI child and maximize it.
- You will notice that there is one more set of form buttons visible.

Workaround:
- Leave the menu outside of the panel.

To reproduce: 
- Use the approach described here to localize the form: https://msdn.microsoft.com/en-us/library/y99d1cd3%28v=vs.100%29.aspx?f=255&MSPPError=-2147217396
- Open the resx file in Visual Studio.

To reproduce: add a RadForm and start the application.

Workaround:
public partial class Form1 : RadForm
{
    public Form1()
    {
        InitializeComponent();
        
    }

    protected override void OnLoad(Size desiredSize)
    {
        this.ElementTree.InitializeRootElement();
        this.RootElement.ApplyShapeToControl = false;
        base.OnLoad(desiredSize);
    }

    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);
        this.RootElement.ApplyShapeToControl = true;
    }
}

Steps to reproduce: 
1. Create Telerik WinForms Application and add two RadForm
2. Select one of forms and set the IsMdiContainer property to true 
3. Select the child form. Open the Properties window and set the following properties at design time: 
 - WindowState to Maximized 
 - ThemeName to Windows8 or any other theme 
4. Run the application and show the child form. The child form is cut off instead maximized. 

Workaround: 
1. Reset the WindowState property at design time
2. Subscribe to the Form`s Load event and set the WindowState property 
private void RadForm2_Load(object sender, EventArgs e)
{
    this.WindowState = FormWindowState.Maximized;
}

To reproduce:

1. Create a RadForm - Form1
2. Change its BackColor at design time
3. Create another RadForm - Form2 
4. Open it at design time. It is expected to have the BackColor coming from the parent form.

Workaround: Set the color in the form's constructor instead of at design time.

How to reproduce: check video and attached project

Workaround: instead of setting the AutoScroll to true of the child form use a RadScrollablePanel

Please refer to the attached sample project.

Workaround:
this.SizeChanged += RadForm1_SizeChanged;
private void RadForm1_SizeChanged(object sender, EventArgs e)
{
    if (this.WindowState == FormWindowState.Maximized  && !this.IsMdiChild)
    {
        this.Region = null;
    }
}

1. 2 Monitors configured. The primary display is 16:9 (laptop), the second display has an aspect ratio is 16:10 (desktop monitor).
2. move sample Telerik WinForm app to secondary display (desktop monitor)
3. Click on maximize button

Result: Application width is more then monitor size, as result application is truncated from right.

The same happens with "RadControls for WinForms Q1 2010 Demos" which I have installed on my PC

To reproduce:
- Add 3 MDI child forms with a lot of gauges.
- Set their WindowState to maximized.
- Show each upon a button click.

Workaround:
Set the state of all forms to normal, before adding a new maximized form.

To reproduce:
public partial class RadForm1 : MyForm
{
    public RadForm1()
    {
        InitializeComponent();
    }
}
public class MyForm : RadForm
{
    public MyForm()
    {
        this.AllowTheming = false;

    }
}