The Process Version is carried over from your previous LR Catalog editing. Unless you "update the process version" it will remain the same. It's best to update the images one-at-a-time based on your usage of the image file. If it looks good with the older process version go ahead and keep it that way. If an image has an issue with Highlight or Shadow detail then that's a good candidate for updating to Process Version 2012. LR will automatically "convert" your settings to the new PV, which may look fine. If not, reset the PV2012 Tone settings to default 0 by clicking on the word 'Tone' in the Basic panel and start over.
At this point it seems random - one set on one photo, another set on another photo of the same file type, sometimes both sets flip flop on the same photo file...
This is most likely caused by applying a Develop preset with the older process version.
Thank you for that! I'm guessing now I accidentally clicked the "update process version" on the histogram on some of them. Explains all!
Interestingly, I do not see the "update process version" button that is said to be on the lower right hand corner of the photo, but the one on the histogram is plain as day.