[Q] Contacts on Google overriding changes in Android 4.0.3 Galaxy S II

Hello!

I have the Samsung Galaxy SII - GT-I9100 model, running unmodified Android 4.0.3 and whenever I make a change to any contact on my phone (it's marked as a Google Contact, btw), it stays that way until I synchronize my account with google, when the contact will then be reverted to the way it is on Google.

I have no idea what's wrong and it has been like this ever since I bought the phone. If I go to my Google account and change a contact through the web, my cell phone will sync and bring the changes from the google server, but the opposite (pushing changes to the server) won't happen.

All my contacts are orgnized and stored in the "My contacts" group. My contacts application is showing only the contacts on the google account, so there's no conflict with any contacts that might be stored locally on the phone (I've deleted all the phone and SIM contacts just to make sure nothing like that gets in the way).

I'd appreciate any help you guys could provide. I'm not willing to root or install any other ROM on this phone, I'd like to keep it stock for several reasons, warranty being one of the most important.

Thank you very much!