Version:           1.9.9 (using 3.5.9, Kubuntu (gutsy) 4:3.5.9-0ubuntu1~gutsy1~ppa1)
Compiler:          Target: i486-linux-gnu
OS:                Linux (i686) release 2.6.22-14-generic

I've received a mail with this content:
**************************************************************
(Headers)
Mime-Version: 1.0
Content-Type: MULTIPART/MIXED;
  BOUNDARY="1926193751-1566499253-1209778611=:29983"
(HEaders)

--1926193751-1566499253-1209778611=:29983
Content-Type: MULTIPART/MIXED; BOUNDARY="1926193751-1566499253-1209778611=:29983"

  This message is in MIME format.  The first part should be readable text,
  while the remaining parts are likely unreadable without MIME-aware tools.

--1926193751-1566499253-1209778611=:29983
Content-Type: TEXT/PLAIN; charset=X-UNKNOWN; format=flowed
Content-Transfer-Encoding: QUOTED-PRINTABLE

Hi --

On Sat, 3 May 2008, I=C3=B1aki Baz Castillo wrote:
blablabla...
blablabla...
blablabla...
**************************************************************


As you see the body starts with "Hi --". When I press "Reply" buttom the original content dissapears. I think it's matching "Hi --" as the signature symbol, that would be a bug since it must be a line just containing "--" (with no spaces or letters).

But in any other similar mail with content starting with "Hi --" I **do** see the content when replying. For example if I generate in Kmail a mail with body:

***********************
Hi --

blabla
blabla
***********************

and receive it, when pressing "Reply" I do see the content. Here the content format is:

Content-Type: text/plain;
  charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline


Maybe a problem with the content format of the first mail?