If the phone was updated from Gingerbread (2.3.x) to ICS (4.0.x), that could be what's causing the problems. A lot of people are having issues with the ICS upgrade.

Sometimes clearing the system cache or doing a factory reset will fix it. Try clearing the system cache first. If that doesn't help, try the factory reset. Just remember the factory reset will erase your phone and password.

To Clear the System Cache Partition , follow these steps...

• To clear the cache partition, turn off the phone.
• Perform a battery pull (Remove battery for 60 seconds)
• With the battery back in, hold the Volume Up Key and the Power Key at the same time until you see the standard "Galaxy SII" logo appear on the screen. Release both buttons and wait 5 seconds. You will see a menu. Use the volume buttons to go up or down, select with the Home button.
• Select "Wipe cache partition" and then the phone will reboot itself.

Also, if your Gmail isn't syncing, go into your settings/accounts and sync, and be sure auto/sync is checked.


Hope this helps.