To remove the formatting in the cell try setting UseOSThemes to false as well. This will prevent any unwanted styling to occur that is caused by your OS. The behavior is caused by texteditor's border. Since the editor is placed inside the cell it's presented this way instead of like an empty grid cell.

this.ultraTextEditor1.UseOsThemes = Infragistics.Win.DefaultableBoolean.False;

Let me know if I answered all of your questions. Also, you are not going to see more of a cell unless you increase the row height.

Well, I guess you have some problem on your website.
Look at the image here: http://www.symmetric.ch/_Downloads/CellMultiLineTest.jpg

ok, next try :-)
Exception was: System.ComponentModel.Win32Exception: The wait operation timed out
I tried to attach a .png file, now I try a .jpg.

Somehow, the attachment did not work ... here next try :-)

Hi Michael

Thank you for the sample. This is almost it :-)

When you look at my screenshot: when the cell is in edit mode all the text is shown,
but when the cell is not in edit mode, only the first line is shown.
How can this be done ?

Also, when the cell is in edit mode, the left side of the cell does not look right.

Thank you already for your effort.
Kind regards
Frank