FCKeditor not working in IE10

At first the editor wasn't appearing at all on pages where it should have been.  After modifying the fckconfig.js file by changing

var sBrowserVersion = navigator.appVersion.match(/MSIE (.\..)/)[1] ;

to

var sBrowserVersion = navigator.appVersion.match(/MSIE ([\d.]+)/)[1] ;

the editor appears but the textarea does not accept input.