Sound Popping when using my maya44usb since installing win 7

Since upgrading to win 7 on my acer aspire 5536 I have been experiencing poppings sounds when listening to audio via usb.
I have run Dpc Latency and this shows spikes.
When I disable W lan drivers in device manager these spikes disappear but the popping noises don't.
I have searched for updates and they all come back as the latest drivers.
I never had this problem with Vista.
I am also using asio drivers for the sound card.
Please help I'm not very computer minded so am having to rely on these forums to solve the issue.

Thankyou