Avast IS Firewall causes high CPU usage with uTorrent

I’m using Avast IS 8.0.1489.

Everytime I’m downloading using uTorrent with Avast Firewall turned on, a process called “System interrupts” consumes a lot of CPU, around 35%.

It goes down to 1 - 1.5% if I stop uTorrent or stop Avast IS Firewall.

It’s currently set to allow all connections for uTorrent in “Application Rules”.

Please help me solve this problem.

Thank you very much.