Sys.ArgumentOutOfRangeException dialog problem when RadEditor is in a Frameset

PROBLEM
Error: Sys.ArgumentOutOfRangeException: Value must be an integer.
Parameter name: x
Actual value was NaN.

DESCRIPTION
You can experience this problem, when the page containing RadEditor is placed in a <frame> in a <frameset> element, which sets the frameborder attribute to "yes" or "no" rather than to an integer, e.g,

<frameset cols="25%,50%,25%">
  <frame src="LeftFrame.aspx" frameborder="no" />
  <frame src="EditorFrame.aspx" frameborder="yes" />
  <frame src="RightFrame.aspx" />
</frameset>

The problem orriginates from the MS AJAX client-side framework which does not calculate position correctly.

SOLUTION
The frameborder attribute specifies whether or not to display borders around a frame and its values could be "0" or "1".
To solve the problem, the "no" and "yes" values of the frameborder attribute should be changed to "0" and a "1" instead, e.g.

<frameset cols="25%,50%,25%">
  <frame src="frame_a.htm" frameborder="0" />
  <frame src="Default.aspx" frameborder="1" />
  <frame src="frame_c.htm" />
</frameset>