Wow, that was quick. Thanks!
I am running both pdflatex and pdftk on my Windows machine without problems..
To clarify: When I say that the comments has disappeared, I mean that the Comments-metabox is still there, and it still says “Add comment”, but shows no comments.
Yes Andrew. The Comments-metabox is there. When there are no comments it says “Add comment” and “No comments yet.”. Then after adding a comment everything looks right – the comment show up under “Add comment”. But next time I load the same page the comment has disappeared. I can still see them on the dashboard though.