How do I get encodeURIComponent() to stop adding &#C2; character to  &#32 ?

Question

I have a form which incorporates a third-party editor (FCKEditor) in place of a textarea. When that is sent to javascript for encoding, I get something like the following:

Some test notes.   And some more test notes.

The issue that I run into is with the ADDITIONAL space put into the string from the form/editor. I have the following code:

var notes = encodeURIComponent(editWin.GetHTML());

and what I end up with is something like this

Some test notes.  &#C2; And some more test notes.

This is causing me a lot of heartburn and my users aren't making it any easier. I've had one colleague direct me to Mozilla Rhino to look at the encoding issue from that perspective, but I was wanting to ask others (forum posters) as well.