How can I make the phone automatically disable mobile connection when calling?

I recently moved from 2G network to 3G. On 2G when I call somebody - the phone automatically suspends the mobile Internet (since it cannot send data and voice at the same time) and activates back when the call ends. Now on 3G I just cannot call when the mobile Internet is active (no matter whether it downloads something or not) - the call is reset immediately. At the same time I can receive calls, i.e. if somebody calls me - the phone rings and I can talk. If I disable the mobile Internet and use WiFi (or do not use any connection) - it works fine. Changing the network type (auto, 3G, etc...) doesn't help. Android 2.3.3. Go Launcher + Go Contacts Ex. Two questions: 1. Is this an issue with the phone? 2. Is there something I can tune inside the phone to make it auto-switch the mobile Internet like it was on 2G (maybe 3rd party application or patch/fix)?