Charset issue in html to text/plain template conversion

Hi,

We have an initial working setup of RT, simple text templates which setup
generic “From:” lines and standard sig block.

RichText is asked however so i’m experimenting with it, and i may have
found some kind of bug.
The requested attachement include a ® entity, which is
still ok in the text/html part
of the outbound mail, however when switching to the text/plain part
thunderbird display a white on
black exclamation mark, used for invalid char.

When inspecting the mail file further, it appear that the ® entity
is converted to the 0xAE char, which
is the ansi value of the entity, however the system is setup for utf8 mails:

------------=_1280785919-7532-2
RT-Attach-Message: yes
Content-Type: text/plain; charset="utf-8"
X-RT-Original-Encoding: utf-8

sig block
Company �

------------=_1280785919-7532-2

Content-Type: text/html; charset="utf-8"
X-RT-Original-Encoding: utf-8

Also there is the “RT-Attach-Message” header left in the text/plain block.