Is it possible for the center image to drift from lp to lp?

Similar experience with CD and SACD. SACD's center almost always shifts to the right. My guess is that my right ear is more sensitive to higher frequencies. But that's just a guess. I just move the chair a little.

:)

I have noticed this with numerous LP's.  I think the absolute phase between L & R channels is crap shoot in the long, arduous rendering of the recording from the master tape to the cutter lathe to the master to the stamper to the record. It only takes a couple microns of displacement from inner to outer walls of the groove to screw this up.

The solution is actually pretty easier - get and use a good balance control.  The ear will ignor the phase difference and center the image based on amplitude with just a minor adjustment (about in 1-2 dB) in L/R balance.

BTW, I've never heard this effect on a digital recording - they all seem to be consistent in this regard on my system.

cousinbillyl, What you described is exactly what I was trying to convey. I assume since your thoughtful answer detailed my concerns, you have thought about it as well.

cleeds, Yes, these things are checked often.

dcbingaman, Your "solution" is very expensive but under consideration regarding future purchases.

All, I've really paid attention, even more, to speaker adjustments. I can say, the issue is not noticed as much as when I first posted, but still there on occasion. I have been tinkering around with acoustic treatments as well. The sonics have been improved greatly. This revelation may have an additional affect of being more sensitive to "this issue"? Thanks!

I found in MY room, some frequencies are more/less reflective which alters the sonic stage a bit.  Depending on your tolerance, you can search for the truth in your room, but I just listen to the music.