iPhone and Lync

Hi everyone.

My employer have decided to use Microsoft Lync as our primary communication system for chat and phone.

I have some problems using Lync on my iPhone.

1. When in a Lync conversation with VOIP, my Lync session is automatically set on hold when a incoming cellular call comes.

2. When in a Lync conversation with VOIP, my phone is automatically locked and I have to unlock phone to hang up. My employer distribute a policy to lock phone since I have my company e-mail.

Anyone have any tips to give?

Regards

Hermod