line 6619 is setting the value into the hidden control
line 6635 is setting the display text
i have lots of textarea in my project, it works well before v1.4
it will be a hard work to change all the textarea to input
so i changed the source code, and it works.
var f=$(_4b7).find("input["+p+"Name=\""+name+"\"]");
// ADD bugfix textarea textbox
if (!f.length) f=$(_4b7).find("textarea["+p+"Name=\""+name+"\"]");
// END ADD