Contacts in outlook doesn't allow to change fonts

Good Afternoon,

O.S: Windows XP SP2
Office: MS Office 2003

I have exported contacts from a csv file into outlook. Now if I open
any of these imported contacts in outlook and change fonts in Notes
section making them for example bold or italic etc, save and close, go
back to the same contact, the changes do not stick.
However if I add or delete something from notes in those contacts, it
does stay.
If I create a new contact within those contacts, it does allow me to
change fonts and keep the changes.
Any suggestions please that why I can not change fonts in the notes
section of imported contacts?

Regards,

Faisal.