Problem with apostrophe

We have having a problem with an apostrophe when used in contractions.

We type:

Character education is part of every child's school day and an important part of our district's overall curriculum and I did not find it to be very effective this year.

Then we go to a second document.

When we return to the first document, this is how it looks (with the ' replacing the '):

Character education is part of every child's school day and an important part of our district's overall curriculum and I did not find it to be very effective this year.

The fonts we are using are Comic Sans and Arial.