Help needed recording vinyl to computer

I just got a new Rega P3 turntable with a Cambridge Audio 640P phono stage. The cartridge is a Dynavector 10x5. I like the sound of it, especially considering there is only about 8 hours on it and it's not fully broken it. However, I'm having a problem recording the audio to my computer.

I have the output of the phono stage plugged into my sound card - a M-Audio Audiophile 24/96 card. It's a great card. However, when recording the audio into Adobe Audition 2.0, I noticed the sound is off center in each channel. Adobe breaks the sound into 2 channels in the waveform, and they are balanced fine. However, it also splits the individual channels in half, giving each a center point in the channel. I noticed that in the left channel, the waveform is mostly above the center line, and in the right channel, the waveform is mostly below the center line.

When I plug a CD player into the sound card, I notice that the sound is perfectly centered in each channel. So I know it is not the sound card at fault. It seems to be either the phono stage or the cartridge (?).

If it's the phono stage, does anyone have any advice what I can do?

I'm very frustrated with this - I'm itching to start recording my vinyl, but don't want to do it if it's not recording right.

Any help would truly be appreciated. Thank you.