This sounds possibly related to a problem I have had in several versions of LR, including (I think) version 6. My problem has been intermittent, and I have found a work-around, so I have never posted a ticket to Adobe about it.
In my case, what happens (sometimes) is this: I make a small selection of images to work on, then process just those images in Develop, and then go to the Print module. Every now and then what shows up in the Print module is not the same as the selection I have been working with.
How do I know that? After having been burned a time or two I got in the habit of leaving the "info" display turned on (press the "I" key) whenever I am in the Print module. At the top of the image shown will be "Page 1 of x" where "x" is the number of images Print thinks are selected. I always cycle through those images a couple of times (right arrow key) to make sure they are the ones I want, before I print.
And sometimes the selection chosen by Print is NOT what I've been working with. What I do then is go back to Library ("G" for Grid) and reselect the ones I want as needed. Then I go back to Print and cycle through these again. It has sometimes taken two round trips back to Library before I get the right selection in Print.
Yes, sometimes the Print module seems to lose the selection that Library and Develop have been working on, so I think there is a communications glitch between Print and the other modules.
I have even printed one selection, then changed to a new selection, and had the old selection still show up in Print.
I also always have "Print Preview" turned on in my printer driver so I have additional verification that the first print to come out is going to be what I expected.
My work-around of checking what Print thinks it is supposed to print, and reselecting back in Library as needed, is quick and works well as long as I remember to check.
I hope this can help your situation.
-Eric
