sonic image shift from my Laptop

I just discovered a pretty crazy phenomena and am wondering if any other PC audiophiles have experienced it.

I recently followed the advice of Jim Smith's "Get Better Sound" book and dialed in my media room for 2channel listening. Using my Sony SACD/DVD player, I was able to lock in a solid center image with outstanding tonal balance and soundstaging. I then hooked up my Sony Laptop which contained a bunch of recently ripped cds and noticed that the sonic image shifted right of center. What's crazy is that both the PC (Via Highface M2) and the DVD player are connected using SPDIF and the Marantz was set to Pure Direct mode which kills all processing. Any Ideas as to what could be going on would be appreciated.
Burn the same cd to the laptop that you used to do your set up and see if the image shifts. I would be suprised if you have not already. If it does then it is due to an anomoly in the laptop playback software. You may need to try a different playback option like Foobar, MediaMonkey, James River plus many others. Report back.
Can you verify the output levels of your DAC using a voltmeter or an oscilloscope?

Recently my preamp has been away for service, so no balance control available. I ran the DAC directly to the power amps using its volume control. There appeared to be a channel imbalance, so following instructions found in the DAC's manual, I input a reference signal to the DAC and measured output in volts of each channel. There was a small difference, so I conclude my DAC needs adjustment.

It may only be coincidence, but this imbalance didn't show up until I began using a laptop as a source.
Thanks for the input Tom6897 and Tobias. Tom, I listened to the same Patricia Barber track from the laptop file and the source CD. Maybe JRiver does have an output issue. I will try some iTunes files.