Sound playing twice while recording/monitoring

I am a “newbee” so please forgive if I miss something simple, but I JUST downloaded the newest version of Audacity (install was smooth), hooked up a brand new Ion TTUSB05 usb turntable and am working with a i7, win 7 pro, 16 gig ram Acer computer. When playing the album alone, the sound is fine, but whenever I either monitor the sound through Audacity or record through Audacity (which I guess requires monitoring) the sound comes out twice - as if it is still playing from the turntable AND playing from Audacity - just one version is a half second delayed from the first version. I’ve tried not selecting “monitor” and that works fine until I record and then it starts to monitor again and I get the two versions of the music playing, again with one version delayed a little. My only solution so far is just to cut off the speakers. I’ve been kind of stuck here and haven’t moved on but from what I can tell, the recorded version is fine. Nothing else unusual except 1) my input level seems very, very high and I had to cut it down to almost nothing to avoid hiss and to get the recording level in the good range and 2) at the end of messing with it for a long while my wireless mouse stopped responding, but I don’t know if that is related. I’ve searched but can’t find this same problem. Any suggestions?

How is the turntable connected to your computer?
How and where are the speakers connected?
(in fact, please describe as clearly as you can how the whole system is set up - we can’t see the set-up)

The turntable is connected by USB port and the speakers are connected in the back to the computer by 3.5 mini stereo jack. There is no separate audio card but the computer does have “intergrated 5.1 audio”. My speakers are just stereo.

Try turning off “Software Playthrough” in the Transport menu.