, sorry. i'm updated.

- maybe you forgot to attach the patch?

i can't reprocedure exact as you. but has 2 case
1. break character (with russian maybe some other language).
2. content is empty (every language).

issue 2: by ck library it's description here:
http://ckeditor.com/forums/Support/Prevent-and-%C2%A0-from-being-inserted-to-dom-element

easy to redo:
1. open feedback dialog
2. copy text from other, paste to content
3. input to email
4. don't focus again content field. click sent button,
email receive will empty.

fix by update ck lib.

issue 1: code send mail fix use transport code is 8bit, because content not suitable make text break.

my patch include lib down at:
http://www.zkoss.org/download/zkckeditor