Can't record vocals?

[Sasha650]

I recently purchased a Yetti Pro mic to record vocals. I imported an mp3 file into audacity and it playes fine (when I have it in the Windows Direct audio host setting. When I use MME the instrumental doesn't play at all, it just moves with the timeline.) Whenever I try to record vocals using windows direct, even if the song is not playing, I get a couple of error messages. "Unanticipated host error" and "Error while opening sound device. Please check the input device settings and the project sample rate." I've tried making sure that the overdub was on, as well as software playthough. I've also tried both of them off, and one off and one on. I'm really not sure what to do? What am I doing wrong?

[steve]

Overdub should be on (selected).
Software Playthrough should be off (not selected).
In the Device Toolbar the recording (Input Device) setting should be set to the USB option (the Yetti) and the playback (Output Device) setting should be set to the sound card output that your headphones are connected to.