Bold being set on entire document

[Steve Watson]

Have a reoccurence of a problem that I thought had gone
away with Office XP. When in word if you mark a small
piece of text and change it to bold the entire is put in
bold. When you undo the command it reverts to only the
marked text as bold.

Any ideas as to what I have done wrong?

 

[Katherine Coombs]

it sounds as though the style is set to automatically update, so when you
make a change to the formatting of the text with that particular style name,
it automatically updates the style to be 'bold" and therefore all text that
is that same style is changed to bold.