It is possible that you have changed the settings of Content subscription web part. Please note that these changes are not applied for current subscriptions but only for new ones.
It would help if you re-new all subscriptions – delete them and create once again. You may delete them on Administration -> Users -> edit -> Notifications tab.
There is a feature in 5.0 version that if you are a Global administrator you may log on as edited user (Administration -> Users -> edit -> General) so you may re-create his/her content subscriptions.
Documentation for Content changes notifications