We are slowly upgrading everyone in our office from XP/Office 2003 to Win7/Office 2010. Out of the 8 people we've upgraded so far, 2 of them have the following issue; When they are creating an email and click To-> and add a group from the contacts list, after sending the email the group explodes and shows all of the contacts without initially expanding it.

Our server is running 6.0.7 and the new computers are running ZCO 7.0 up from 5 and 6 previously. All of the computers are configured and setup exactly the same. So why do 6 work and the other 2 don't? This sounds like a ZCO issue, but it could be something else.