Mailitem Copy() loose HTML format

I'm writing a small app that would copy mail messages based on some sort
rule.
I'm having problems copying Mailitems, since it loose html format of the
duplicated messages.

I'm using Outlook 2007 SP3, VS2010 and C#. The mailserver is Kerio 7.2
with its Kerio Offline Connector;

The code is quite simple and the node is the simple Mailitem.Copy() method:

Outlook.MailItem m_cpy = mail.Copy();

I also tried to force the HTMLBody property:

m_cpy.HTMLBody = mail.HTMLBody;
m_cpy.Save();

but...

Mailitem Copy() loose HTML format