Note: ONLY do this if you have been saving your contacts as Google contacts, NOT as "phone" contacts. How can you tell? If you open a specific contact, under connected via, you should see the Google multicolored G icon for Google contacts - if you see a grey and white icon instead (only), it's a phone only contact and you are not backing them up. You've been warned. OK to fix a corrupt Google Contacts sync issue, do the following steps.
Try going to Settings, Accounts, Google, tap on your gmail account, shut off Sync Contacts. Restart the phone. Go to Settings, Applications, Application Manager, slide right twice to ALL, scroll down to Contacts, tap Force Stop, tap Clear Cache, tap Clear Data. Back out and then go back to Settings, Accounts, Google, tap your gmail account, and turn back on Sync Contacts. Wait a few minutes for it to redownload your contacts from Google. Then try a call.