SugarCRM VM Time drift

Hi, 

anyone had a time drift issue between SugarCRM running on a VM and another server like Exchange used to sync contacts, calls, meetings, etc. ? After about a month, the time is different on the VM vs the Exchange server and the sync stop working.

Some are using a NTP Server and run a cron each day to sync.
Anyone with experience with this issue ?

Thanks, 

Jonathan