iPhone 4s wifi dont work when bluetooth connected

I just bought an iPhone 4s through T-Mobile the 16GB Black ios 5.01

Iv realised that when my bluetooth headset is connected to the phone as well as the Wi Fi, the wi fi does not seem to work and if it does it is very slow, and the location services also stop working or are very slow,

As soon as I turn the bluetooth headset connection off and back to the phone, the wifi and location services both seem to work fine

Is this a problem with all iPhone 4s models or is this a specific fault on mine and shall I return?

All advice highly appreciated