Arrow keys (up and down) don't scroll the first row which is outside of the viewport. One way to reproduce this is to scroll down, then select the topmost visible row and press the Up arrow key in order to select the row above. This should scroll the view a bit up in order to see the previous row which is now selected.
Currently, this doesn't work when using a custom implementation of the GridViewCell class.
The issue is reproducible when GroupRenderMode is set to Flat.

To work this around, you can manually scroll to the row.

public MainWindow()
{
	InitializeComponent();
	this.gridView.AddHandler(RadGridView.KeyUpEvent, new KeyEventHandler(OnGridViewKeyUp), true);
}

private void OnGridViewKeyUp(object? sender, System.Windows.Input.KeyEventArgs e)
{
	if (e.Key == Key.Up || e.Key == Key.Down)
	{
		Dispatcher.BeginInvoke(new Action(() =>
		{
			var currentCell = gridView.CurrentCell;
			var row = currentCell.ParentRow;

			// Since the VisualOffset proeprty is protected and you are already inheriting the GridViewRow class, you can just expose it through an extra property in the CustomGridViewRow, instead of using reflection like in this example.
			var visualOffsetPropInfo = typeof(Visual).GetProperty("VisualOffset", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic); 			
			var offset = (Vector)visualOffsetPropInfo.GetValue(row);
			if (offset.Y < 0)
			{
				row.BringIntoView();
			}
		}));
	}
}

Currently, when you cancel the Filtering event the field filter (displayed when FilteringMode="FilterRow") will clear any entered text and the funnel icon won't change its color (like when the filter is active). Add an option in the Filtering event, similar to the Sorting event which allows you to manually set the sorting state of the column which will affect the UI (showing and changing the sort indicator icon).

In the case with the Filtering event, there should be an option if the funnel icon should be highlighted. In other words the setting should allow you to manually say if the filter is active or not. Also, the input text in the field filter should be preserved and possible an option to change this value may be added in the event arguments. This will allow you to implement custom filtering and keep the UI state of the field filter.

Scrolling performance is degraded when RowStyle/RowStyleSelector that sets Template property is explicitly applied

1. Select the first row.
2. Hit Ctrl-End to jump to the end of the list. 
3. Hold down the Shift key and select the last row. 
4. Scroll up and notice that everything between the first page and the last page is not selected.

* there is a sample project attached in the support thread

ArgumentOutOfRandeException in FlatLayoutStrategy.RealizeRows(). The exception occurs if RadGridView.GroupRenderMode="Flat"

New row in Bottom position is not visible in the child grid when the grid has no items

These issues should be resolved with lib version 2014.3.1110.

Application hangs on start up if GroupRenderMode is set to Nested, there is a column with Width Star and a group descriptor applied.

This problem is reproducible only in WPF and can be observed on both Row Context Menu and Header Context Menu QSF examples.

The fix will be available with Q2 2015 version.

The problem was initially reproduced by TestStudio users. It can also be reproduced with a codedUI test where the editor is searched by its AutomationID.

Error Message:

Microsoft.VisualStudio.TestTools.UITest.Extension.UITestControlNotFoundException: The playback failed to find the control with the given search properties. Additional Details: 
TechnologyName:  'UIA'
ControlType:  'Text'
AutomationId:  'CellElement_2_1'