If you had a custom title in the old version, then yes. What we did for 7.1 is added a new dedicated custom title field. The first one is stricly a post based title now, however I didn't want to overwrite those on the upgrade.
You can edit everyones new custom title in the control panel. Once everyone has that set then you can go into the Post based titles section and check the box at the bottom to reset those titles so they display correctly.
A bit confusing, but hopefully that make sense.
