I've still got ruined labels.
Print on plain paper until you get it right. That's what I do.
I wish I could help but I've never seen Win8 up close... Maybe, just maybe, you are viewing the PDFs in a different kind of software now (could be something that's integrated in Windows now), that does not offer 'print to fit'?
I use FoxIt Reader as a PDF viewer, it offers that option, maybe you could install that and see if it helps. It's free.
As for the pictures, seems like Win8 is 'helpfully' showing them to you the right side up when in reality they aren't. Do you have an image editing program you could open them in, to check?