Outlook contacts notes formatting

I've got a problem with the Notes area in Outlook 2007 contacts (also had it
in Outlook 2003).

There are SOME contacts where I cannot change the formatting of any text in
the notes area and make it stick.

For example, I can make a line bold (or change font, or font size, or
anything), save the contact, and when I reopen it, whatever I changed in
formatting is gone. I can change the actual words, delete words, add words,
etc and they stick. But I can't change any formatting.

I have done "Clear formatting" to no avail.

I have gone so far as to cut/paste the entire notes area into a plain old
Notepad .txt file, deleted all the text from the notes area, saved and
reopened the contact to confirm it's all gone, done a copy/paste from the
.txt file into the notes area, visually seen that it's all plain text, saved
and reopened the contact, and ... the formatting all returns as if I hadn't
done anything.

Cannot find answers online, either. Anyone else ever seen this? And note
that it's not ALL contacts, just some, with no rhyme or reason that I can
see.

Drives me nuts.