Recording issues, odd results...what is wrong?

Happy fourth,

I am recording my vocals for the first time in Sonar. I am having a strange problem that I know you can solve for me.

I am using a Delta 66 with the latest drivers. I am using Sonar Pro 3.1.1

I have my output on the Deltas 1/2 and my Mic is in the Third input.

I am using about 53% cpu and 11.5 latency 512.

This is what happens,
I create an audio track and then select the delta's third input and the tracks input.
I then hit record arm and began a loop recording. It might make it once through the recording fine but one it makes another pass the audio sounds as if it has been slowed down in a granular synth kind of way. Choppy and about 20bpm less that the original take. It really messes up when I add a buss/pre effect. If I delete the track all is back to normal. What am I doing wrong?

Thanks!!!

Maji