Periodic IP Conflict with my iMac since 5.1 update

Hi,

Ever since I updated my Apple TV 3 with iOS 5.1, the ATV regularly ends up sharing an IP address with my iMac (2007) with Snow leopard. This never occured before the update. Both are set up with automatically assigned IPs through DHCP. I can fix the issue by rebooting my 2Wire modem but the issue reoccurs, usually about 2 days later.

I did at one point assign static IP addresses to all devices on the network but this did not stop the problem from reoccuring as it seems the Apple TV did not stick to the assigned IP.

Aside from the iOS update, I did add a second iTunes account to the ATV as well.

Has anyone else experienced this issue? Anyone know how I can solve it?

Cheers