"known issue"
have the same problem.
What you do is, edit HTML Editor on the update page and click on the lighning symbol next to the text area field called "initial Value" and select the appropriate field from the recordset. This will remove the wrong ""s.
So that the code line looks something like:
$WARichTextEditor_1 = CreateRichTextEditor ("yourtextarea", "HTMLEditor/", "640px", "480px", "Default", "../custom/your_Updatefile_yourtextarea.js", "".$row_WADAyourtable['yourtextarea'] ."");