Is the THX Logo Off-Center?
 

I always noticed the THX logo at the beginning of movies wasn't centered on my tv. Finally I went into the service menu and centered it, but when I checked the VE over-scan pattern, that was then off-center. It seems obvious that VE's over-scan pattern would be better for setting this.

Am I crazy or is the THX logo not centered?

You didn't ID what TV you have, but it's been established that the VE Overscan 4:3 image is not centererd.

I first verified the Center Point on my 16:9 screen (Toshiba 50H81) using (V) string/weight and (H) string / tape (both measured V & H Center vs. TV inside frame bezel). Then using AVIA, I adjusted the Overscan to 3% T&B, 4% L&R side and correct / aligned the convergence in the 56-pt. Convergence Service MODE option.

AVIA 16:9 Anamorphic Overscan image

Afterwards, I looked at the VE Overscan 4:3 image and if you view the digital image, . . . you'll see that it is off, towards the top right when compared to the above Centered AVIA 16:9 Anmorphic Overscan image.

VE 4:3 Overscan (stretch using TW1) image

Interestingly, the VE Anamorphic 16:9 Snell & Wilcox screen is Centered correctly vs. VE 4:3 Overscan image.

So, in reality, the THX Logo that you centered was the correct alignment for your TV. Fine point corner adjustments can be made using AVIA 16:9 Overscan Test Screen.

Hope this helps,
Phil