unknown language 100% error in microsoft outlook 2003

[tintincute]

Hi
i re-installed my PC from scratch and just had it running. I checked my
email using my email clients microsoft outlook 2003 SP3 and it seems to be
working good except when I sent email, every time I sent an email in the
subject it has always this error [unknown language 100%]

does anybody have any idea what's causing this? I also installed an
antivirus Gdata 2010 the newest one.

Thanks