iTead BT and WiFi Shield

Hi guys, I'm facing the problem descrived below and would like to see if you could help me.

I have an iTead BT V2.2 and an Official Arduino Wifi shield.

They are both working fine by themselves but when I plug both at the same time then the Wifi shield is not able to find anymore any of the Wifi networks around. I'm running the original ScanNetworks Example.

I'd guess there is some type of conflict between the BT and WiFi Shields but can't find it...

Any hints?

Many thanks in advance, Simon