Is your image centred?

You cartridges could be magnetized and or you could have a loose wire or connection on the turntable at the cartridge end or the interconnect end.

I would demagnetize the cart then clean the connections to make sure they are good and tight and treat with Pro Gold or other. Also, stylus wear could be a problem or VTA or Azimuth could be off. Last if you are using a tubes in the phono section they could be weak tubes too.
That's just my opinion.

I agree with both Stringreen and Dan_Ed. Most pop music recordings are multi-miked, multi-tracked and mixed (up) in post-production engineering. The end result is typically an imaging and soundstaging mish-mash, and the better the playback system the more obvious these engineering manipulations become. This is one reason we dislike most popular music recordings. If you listen on anything more resolving than a 1965 AM car radio, they sound completely fake. (Singers who can't sing are another reason, but that's for another thread!)

Good classical, jazz, folk and blues recordings are another matter. They provide solid, pinpoint imaging that stays put - assuming your components and setup are good of course. (I wouldn't bet on a Grado for imaging or soundstaging though. Accurate reproduction is not what Grado's are about.)

I have had the same chronic issue, also with a Grado cartridge (Statement Reference), which did not occur with cd. I have wondered whether the Grado was off or just more sensitive than other cartridges. It was improved by readjusting azimuth, and to a lesser extent, anti-skate. Hoping that buying and using a test record can fine-tune setup and complete the solution. Mine was also noticeably affected by the tubes in the phono stage. My next preamp will definitely have a balance control.

It's most likely your system telling you what you want to hear. :) If the image shifts on the same record, then you may have problems as stated such as wiring or room characteristics like doors that will shift images if they are open or closed. If the images on the same record stay consistent after different plays but are always in the same place, then that's the recording. If you listen to records that have had different masterings, you often find the instruments have been moved to different locations.

You say cd's are no problem, ie. it is something in your phono stage, turntable or cartridge. Cartridge allignment, especially azimuth has a lot to do with channel equalization. Otherwise I would say you are properly hearing what is on some recordings.

I don't understand you don't hear this lack of centeredness on cd as well. I hear it on both cd and vinyl, drives me nuts at times. The people mixing some of these horrors gotta be idiots.

Anyway, perhaps the problem is in your digital?

I also notice as my system increases in resolution, much greater air and spaciousness around images decreases the bothersome aspects of strange production values. A smaller, more focused soundstage makes these anomolies more bothersome to me.