On the main page the date for latest form submission is not updating on a sub user account.

Hi,

Have them try clearing their forms cache:

http://www.jotform.com/help/229-How-to-Clear-your-Form-Cache

If that does not allow for the proper dates to show, let us know the username or email address of the sub-user and account and we will be happy to have a look to see what is going on.