Since the beginning of August, Google Calendar Sync stopped definitively working.
So he had to find a compelling alternative to continue to synchronize my calendar, my contacts to outlook ... to my cell phone.
After several searches and tests, I stopped on the addon gSyncit.
It works with Outlook 2003/2010/2013 in 32 bit and 64 bit
The free version will sync your calendar in both directions (Outlook / Gmail) and contacts (50max). Constraint: a count of 15 seconds every time you open Outlook.
It is important to download the version 4.0 * that solves the security problems associated with google.