Updating information in Custom fields within a tab not saving since update to 4.7.0
Hi I did manage to test the same against 4.7.0 and we do have an issue. so, please raise an issue for the same

Also I did manage to test the same against Civicrm Version 4.6.11 and everything works perfectly. so at this time I would recommend you to install civicrm Version 4.6.11 for time being and wait for the next version and see if that gets fixed